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1.
Ecotoxicol Environ Saf ; 208: 111605, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396125

RESUMO

This is a novel study about responses of leaf photosynthetic traits and plant mercury (Hg) accumulation of rice grown in Hg polluted soils to elevated CO2 (ECO2). The aim of this study was to provide basic information on the acclimation capacity of photosynthesis and Hg accumulation in rice grown in Hg polluted soil under ECO2 at day, night, and full day. For this purpose, we analyzed leaf photosynthetic traits of rice at flowering and grain filling. In addition, chlorophyll content, soluble sugar and Malondialdehyde (MDA) of rice leaves were measured at flowering. Seed yield, ear number, grain number per ear, 1000-grain weight, total mercury (THg) and methylmercury (MeHg) contents were determined after harvest. Our results showed that Hg polluted soil and ECO2 had no significant effect on leaf chlorophyll content and leaf mass per area (LMA) in rice. The contents of soluble sugar and MDA in leaves increased significantly under ECO2. Mercury polluted soil treatment significantly reduced the light saturated CO2 assimilation rate (Asat) of rice leaves only at flowering, but not at grain filling. Night ECO2 greatly improved rice leaf water use efficiency (WUE). ECO2 greatly increased seed yield and ear number. In addition, ECO2 did not affect THg accumulation in rice organs, but ECO2 and Hg treatment had a significant interaction on MeHg in seeds, husks and roots.


Assuntos
Dióxido de Carbono/análise , Mercúrio/toxicidade , Compostos de Metilmercúrio/toxicidade , Oryza/metabolismo , Fotossíntese/efeitos dos fármacos , Poluentes do Solo/toxicidade , Bioacumulação , Clorofila/metabolismo , Grão Comestível/química , Grão Comestível/efeitos dos fármacos , Monitoramento Ambiental/métodos , Mercúrio/análise , Compostos de Metilmercúrio/análise , Oryza/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Folhas de Planta/química , Folhas de Planta/efeitos dos fármacos , Raízes de Plantas/química , Raízes de Plantas/efeitos dos fármacos , Solo/química , Poluentes do Solo/análise
2.
Ecotoxicol Environ Saf ; 208: 111769, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396087

RESUMO

Soils contaminated with heavy metals such as Chromium (Cr) and Cadmium (Cd) severely impede plant growth. Several rhizospheric microorganisms support plant growth under heavy metal stress. In this study, Cr and Cd stress was applied to in vitro germinating seedlings of a Legume plant species, Sesbania sesban, and investigated the plant growth potential in presence and absence of Bacillus anthracis PM21 bacterial strain under heavy metal stress. The seedlings were exposed to different concentrations of Cr (25-75 mg/L) and Cd (100-200 mg/L) in Petri plates. Growth curve analysis of B. anthracis PM21 revealed its potential to adapt Cr and Cd stress. The bacteria supported plant growth by exhibiting ACC-deaminase activity (1.57-1.75 µM of α-ketobutyrate/h/mg protein), producing Indole-3-acetic acid (99-119 µM/mL) and exopolysaccharides (2.74-2.98 mg/mL), under heavy metal stress condition. Analysis of variance revealed significant differences in growth parameters between the seedlings with and without bacterial inoculation in metal stress condition. The combined Cr+Cd stress (75 + 200 mg/L) significantly reduced root length (70%), shoot length (24%), dry weight (54%) and fresh weight (57%) as compared to control. Conversely, B. anthracis PM21 inoculation to seedlings significantly increased (p ≤ 0.05) seed germination percentage (5%), root length (31%), shoot length (23%) and photosynthetic pigments (Chlorophyll a: 20%; Chlorophyll b: 16% and total chlorophyll: 18%), as compared to control seedlings without B. anthracis PM21 inoculation. The B. anthracis PM21 inoculation also enhanced activities of antioxidant enzymes, including superoxide dismutase (52%), peroxidase (66%), and catalase (21%), and decreased proline content (56%), electrolyte leakage (50%), and malondialdehyde concentration (46%) in seedlings. The B. anthracis PM21 inoculated seedlings of S. sesban exhibited significantly high (p ≤ 0.05) tissue deposition of Cr (17%) and Cd (16%) as compared to their control counterparts. Findings of the study suggested that B. anthracis PM21 endured metal stress through homeostasis of antioxidant activities, and positively impacted S. sesban growth and biomass. Further experiments in controlled conditions are necessary for investigating phytoremediation potential of S. sesban in metal-contaminated soils in presence of B. anthracis PM21 bacterial strain.


Assuntos
Bacillus anthracis/fisiologia , Metais Pesados/toxicidade , Sesbania/fisiologia , Poluentes do Solo/toxicidade , Bacillus anthracis/metabolismo , Biodegradação Ambiental , Cádmio/metabolismo , Catalase/metabolismo , Clorofila , Clorofila A/metabolismo , Cromo/análise , Germinação/efeitos dos fármacos , Ácidos Indolacéticos , Metais Pesados/análise , Plântula/metabolismo , Sesbania/metabolismo , Sesbania/microbiologia , Solo , Poluentes do Solo/análise
3.
Ecotoxicol Environ Saf ; 208: 111584, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396107

RESUMO

Cadmium (Cd) is highly toxic for plant metabolic processes even in low concentration due to higher retention rates, longer half-life and non-biodegradable nature. The current study was designed to assess the bioremediation potential of Cd tolerant PGPR, Serratia sp. CP-13 together with two differentially Cd tolerant maize cultivars (MMRI-Yellow, Sahiwal-2002) selected amongst ten cultivars after screening. The maize cultivars were grown under different Cd treatments (0, 6, 12, 18, 24, 30 µM) in Petri plates both with and without Serratia sp. CP-13 inoculation. Treated plants were analyzed for their biomass accumulation, chlorophylls, carotenoids, proline, anthocyanin, protein, malondialdehyde (MDA), H2O2 as well as for antioxidants (POD, SOD, CAT) and mineral elements (Ca, Mg, Zn, K, Fe, Na, Cd). The maize cultivar MMRI-Yellow (tolerant) and Sahiwal-2002 (sensitive) exhibited significant reduction in leaf area, nutrient contents, plant biomass, activity of antioxidants, total proteins, photosynthetic pigments as well as flavonoids with increased production of H2O2, proline, MDA and relative membrane permeability (RMP) under Cd stress. However, this reduction was cultivar specific and recorded higher in cv. Sahiwal-2002 as compared to MMRI-Yellow. Application of Serratia sp. CP-13 significantly augmented plant biomass, photosynthetic pigments, antioxidative machinery, as well as flavonoids and proline while diminishing H2O2, RMP MDA production even under Cd stress in studied cultivars. Furthermore, CP-13 inoculation assisted the Cd stressed plants to sustain an optimal level of essential nutrients (Ca, Mg, Zn, K, Fe) except for Na and Cd which responded antagonistically. It was inferred that both inoculated maize cultivars exhibited better health and metabolism but substantial Cd tolerance was acquired by the sensitive cv. Sahiwal-2002 than the tolerant cv. MMRI-Yellow under applied Cd regimes. Furthermore, studied maize cultivars depicted maximum Cd tolerance in order of 30 < 24 < 18 < 12 < 6 < 0 µM Cd treatments under Serratia sp. CP-13 inoculation. Findings of current work highlighted the importance of Serratia sp. CP-13 and its inoculation impact on morpho-physio-biochemical attributes of maize growth under Cd dominant environment, which is likely an addition towards efficient approaches for bacterially-assisted Cd bioremediation and minimal Cd retention in edible plant parts.


Assuntos
Cádmio/toxicidade , Serratia/fisiologia , Poluentes do Solo/toxicidade , Zea mays/fisiologia , Antioxidantes/metabolismo , Biodegradação Ambiental , Transporte Biológico , Biomassa , Cádmio/metabolismo , Clorofila/metabolismo , Peróxido de Hidrogênio/metabolismo , Fotossíntese , Folhas de Planta/metabolismo , Serratia/metabolismo , Poluentes do Solo/análise , Poluentes do Solo/metabolismo , Zea mays/metabolismo , Zea mays/microbiologia
4.
Ecotoxicol Environ Saf ; 208: 111627, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396147

RESUMO

A pot study was conducted to explore the effectiveness of zinc oxide nanoparticles (ZnO NPs) foliar exposure on growth and development of wheat, zinc (Zn) and cadmium (Cd) uptake in Cd-contaminated soil under various moisture conditions. Four different levels (0, 25, 50, 100 mg/L) of these NPs were foliar-applied at different time periods during the growth of wheat. Two soil moisture regimes (70% and 35% of water holding capacity) were maintained from 6 weeks of germination till plant harvesting. The results revealed that the growth of wheat increased with ZnO NPs treatments. The best results were found in 100 mg/L ZnO NPs under normal moisture level. The lowest Cd and highest Zn concentrations were also examined when 100 mg/L NPs were applied without water deficit stress. In grain, Cd concentrations decreased by 26%, 81% and 87% in normal moisture while in water deficit conditions, the Cd concentrations decreased by 35%, 66% and 81% compared to control treatment when ZnO NPs were used at 25, 50 and 100 mg/L. The foliar exposure of ZnO NPs boosted up the leaf chlorophyll contents and also decreased the oxidative stress and enhanced the leaf superoxide dismutase and peroxidase activities than the control. It can be suggested that foliar use of ZnO NPs might be an efficient way for increasing wheat growth and yield with maximum Zn and minimum Cd contents under drought stress while decreasing the chances of NPs movement to other environmental compartment which may be possible in soil applied NPs.


Assuntos
Cádmio/toxicidade , Secas , Nanopartículas/química , Poluentes do Solo/toxicidade , Triticum/fisiologia , Óxido de Zinco/química , Cádmio/análise , Clorofila , Grão Comestível/química , Poluição Ambiental , Estresse Oxidativo , Folhas de Planta/química , Solo , Poluentes do Solo/análise , Triticum/crescimento & desenvolvimento , Água , Zinco/análise
5.
Food Chem ; 335: 127621, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32738533

RESUMO

In the present study, the effects of blue LED light on the regreening of citrus fruit were investigated in an in vitro system of Valencia orange flavedos. The results showed that blue LED light irradiation induced regreening in the flavedos. After four-week culture in vitro, the flavedos exhibited obviously green color in the blue LED light treatment, while the flavedos in the control were still in orange color. During the regreening process, the blue LED light treatment induced chlorophyll accumulation, and substantially altered the carotenoid composition in the flavedos. Compared with the control, the content of 9-cis-violaxanthin was decreased, while the contents of lutein, ß-carotene, and all-trans-violaxanthin were increased by blue LED light. In addition, gene expression results showed that the up-regulation of CitLCYe and down-regulation of CitLCYb2 by blue LED light led to a shift from ß,ß-branch to ß,ε-branch of the carotenoid biosynthetic pathway.


Assuntos
Citrus sinensis/metabolismo , Citrus sinensis/efeitos da radiação , Luz , Pigmentação/efeitos da radiação , Carotenoides/metabolismo , Clorofila/metabolismo , Citrus/metabolismo , Frutas/metabolismo , Frutas/efeitos da radiação , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Xantofilas/metabolismo , beta Caroteno/metabolismo
6.
J Environ Sci (China) ; 99: 187-195, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33183696

RESUMO

Periodically hydrologic alterations driven by seasonal change and water storage capacity management strongly modify physicochemical properties and chlorophyll-a (Chl-a) and their interactions in dam-induced lakes. However, the extent and magnitude of these changes still remain unclear. This study aimed to determine the effects of periodically hydrologic alterations on physicochemical variables and Chl-a in the dam-induced urban Hanfeng Lake, upstream of Three Gorges Reservoir. Shifts in Chl-a and 13 physicochemical variables were recorded monthly in the lake from January 2013 to December 2014. Chl-a was neither seasonal nor inter-annual differences while a few physical variables such as flow velocity (V) exhibited significantly seasonal variabilities, and chemical variables like total nitrogen (TN), nitrate-nitrogen (NO3-N), total phosphorus (TP), dissolved silica (DSi) were markedly inter-annual differences. Higher TN:TP (40:1) and lower NO3-N:DSi (0.8:1) relative to balanced stoichiometric ratios suggested changes in composition of phytoplankton communities and potentially increased proportion of diatom in Hanfeng Lake. Chl-a was predicable by combination of dissolved oxygen (DO), TN and DSi in dry season, and by V alone in wet season. During the whole study period, Chl-a was solely negatively correlated with TN:TP, indicating decline in N concentration and increase in P could therefore increase Chl-a. Our results highlight pronounced decoupling of linkages between Chl-a and physicochemical variables affected by periodically hydrologic alterations in dam-induced aquatic systems.


Assuntos
Eutrofização , Lagos , China , Clorofila/análise , Clorofila A , Monitoramento Ambiental , Nitrogênio/análise , Fósforo/análise
7.
Chemosphere ; 263: 127943, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32822939

RESUMO

Due to the characteristics of both rare earth elements (REEs) and nanoparticles (NPs), Y2O3 NPs have been widely used in the fields of medicine, military industry, and agriculture, especially in the areas of electricity, light, magnetism, and catalysis. Given this widespread use, it is inevitable that Y2O3 NPs and soluble Y3+ will enter bodies of water through the processes involved in their preparation, application, and disposal. We sought to investigate the toxicities of Y2O3 NPs and Y3+ ions on rice seedlings (Oryza sativa L.), as well as the uptake and distribution of Y2O3 NPs under hydroponic conditions. Our results indicated that Y2O3 NPs and released Y3+ had no significant effect on the germination rate of rice. However, high concentrations of Y2O3 NPs (50 and 100 mg/L) delayed seed germination. As for rice root elongation, low concentrations (1, 5, and 10 mg/L) of Y2O3 NPs had a positive effect. Notably, when Y2O3 NPs concentration reached 20 mg/L and higher, root elongation was significantly inhibited. According to the physiological and biochemical characteristics of rice seedlings under Y stress, Y2O3 NPs ranging from 20 to 100 mg/L significantly reduced chlorophyll contents and root activity. Using ICP-MS and TEM analyses, Y2O3 NPs and Y3+ were shown to be mainly absorbed and accumulated in the roots. With Y2O3 NPs exposure, the Y transport coefficient from the roots to the shoots of rice was 1.94-7.55%. Comparatively, Y3+ ions had an insignificant effect on plant growth, with the phytotoxicity of Y being mainly produced by Y2O3 NPs.


Assuntos
Nanopartículas/toxicidade , Oryza/fisiologia , Transporte Biológico , Clorofila , Cultura , Germinação/efeitos dos fármacos , Hidroponia , Íons/farmacologia , Oryza/efeitos dos fármacos , Oryza/crescimento & desenvolvimento , Raízes de Plantas/efeitos dos fármacos , Plântula/efeitos dos fármacos
8.
Food Chem ; 339: 127818, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32854038

RESUMO

Native extracts from orange peels were obtained by a conventional method using acetone and, an alternative method using ionic liquid (1-butyl-3-methylimidazolium chloride ([C4mim]Cl)). The bioaccessibilities and cellular uptakes of carotenoids, esters and chlorophylls were evaluated, since the influence of esterification on bioaccessibility and bioavailability is not well established. For this, the extracts were emulsified, submitted to in vitro simulated digestion model according to the INFOGEST protocol, followed by uptake by Caco-2 cells. Compounds were separated, identified and quantified by HPLC-PDA-MS/MS. After digestion, 22.0% and 26.2% of the total carotenoids and 45.9% and 68.7% of the chlorophylls were bioaccessible from the acetone and [C4mim]Cl extracts, respectively. The bioaccessibilities of xanthophylls and carotenes were significantly higher than those of the mono- and diesters. The uptake by Caco-2 cells varied from 130.2 to 131.9 ng/mg cell protein for total carotenoids and from 243.8 to 234.2 ng/mg cell protein for chlorophylls in the acetone and [C4mim]Cl extracts, respectively. In general, xanthophylls and esters were better absorbed than carotenes.


Assuntos
Carotenoides/farmacocinética , Fracionamento Químico/métodos , Clorofila/farmacocinética , Citrus sinensis/química , Disponibilidade Biológica , Células CACO-2 , Carotenoides/análise , Carotenoides/isolamento & purificação , Clorofila/análise , Clorofila/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Digestão , Ésteres/farmacocinética , Frutas/química , Humanos , Líquidos Iônicos/química , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacocinética , Espectrometria de Massas em Tandem , Xantofilas/análise , Xantofilas/isolamento & purificação , Xantofilas/farmacocinética
9.
Ecotoxicol Environ Saf ; 207: 111198, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32905932

RESUMO

Cd pollution in farmland is becoming a serious problem because it affects the safety of rice production and human health. Salicylic acid (SA) plays crucial roles in plant development and mediates plant responses to biotic and abiotic stress. This study assessed the molecular and physiological mechanisms of SA spraying effects on Cd tolerance and Cd accumulation in rice. Spraying of 0.1 mM SA had no great effect on the agronomic traits of rice, but significantly decreased Cd accumulation in rice grains, and SA spraying increased the Cd contents in leaves (only at the mature stage) and decreased the Cd contents in panicles (only at the filling and mature stage), but had no evident impact on the Cd content of other tissues and other growth stages. SA spraying reduced Cd accumulation in rice grains by promoting the deposition and fixation of Cd in the cell wall of leaves, thus preventing Cd being transferred from leaves to rice grains at the filling stage. SA spraying also decreased Cd toxicity by reducing H2O2 and MDA accumulation and increasing the chlorophyll content in rice leaves. Furthermore, SA spraying remarkably decreased Cd accumulation in rice grains by modulating the expression level of the genes associated with Cd translocation and accumulation to control the Cd accumulation in rice. Hence, SA spraying reduced the inhibition of Cd on the plant height caused by Cd and increased the dry weight of shoots in the vegetative growth period of rice seedlings, and it reduced Cd transport from leaves to grains, thus reducing Cd content in rice. These findings provide a novel perspective and a new method for reducing Cd accumulation in rice.


Assuntos
Cádmio/toxicidade , Oryza/metabolismo , Substâncias Protetoras/farmacologia , Ácido Salicílico/farmacologia , Poluentes do Solo/toxicidade , Cádmio/metabolismo , Clorofila/metabolismo , Poluição Ambiental , Humanos , Peróxido de Hidrogênio/metabolismo , Folhas de Planta/metabolismo , Plântula/efeitos dos fármacos , Poluentes do Solo/metabolismo , Estresse Fisiológico/efeitos dos fármacos
10.
Ecotoxicol Environ Saf ; 207: 111233, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32916528

RESUMO

Growth of microcystin-producing cyanobacteria in Lake Okeechobee (Florida, USA) and surrounding waters has resulted in adverse health impacts for humans and endangered species, as well as significant economic losses. As these issues worsen, there is growing pressure for efficacious solutions to rapidly mitigate harmful algal blooms (HABs) and protect critical freshwater resources. Applications of USEPA-registered algaecides as management tactics meet many decision-making criteria often required by water resource managers (e.g., effective, scalable, selective), but have not yet been evaluated on a large scale within the Lake Okeechobee waterway. This study was conducted to bolster the peer-reviewed database for available management tactics against microcystin-producing cyanobacteria in waters of this region. Laboratory-scale experiments can be conducted first to minimize uncertainty at larger scales and improve confidence in decision-making. In this study, samples containing microcystin-producing cyanobacteria collected from Lake Okeechobee were exposed to several USEPA-registered algaecides in laboratory toxicity experiments. Responses of target cyanobacteria were measured 3 days after treatment (DAT) in terms of cell density, chlorophyll-a concentrations, and phycocyanin concentrations. Based on responses of the cyanobacteria, minimum effective exposure concentrations were identified for each algaecide. Microcystin release (i.e. proportion of total microcystins in the aqueous phase) was measured and compared 1 DAT among effective exposures. Total microcystin concentrations were measured in effective treatments at 1, 4, and 9 DAT to discern potential for microcystin persistence following exposures to the effective formulations and exposure concentrations. Overall, several formulations including GreenClean Liquid® 5.0, GreenClean Liquid® 5.0 combined with Hydrothol® 191, and the copper-based algaecides evaluated (Algimycin® PWF, Argos, Captain® XTR, Cutrine® Ultra, and SeClear®) achieved significant and similar effects on target cyanobacteria. The chelated copper-based formulations (Algimycin® PWF, Argos, Captain® XTR, and Cutrine® Ultra) resulted in relatively less microcystin release 1 DAT and lesser total microcystin concentrations 4 DAT. At 9 DAT, total microcystin concentrations were significantly lower than in untreated controls in all treatments evaluated. These results provide the necessary comparative performance data for preliminary decision-making and designing additional studies at larger scales. Importantly, the comparative toxicity data and approach provided in this study demonstrate the initial steps for development of site-specific management strategies for Lake Okeechobee and other areas impacted by harmful algal blooms with large spatial and temporal scales.


Assuntos
Cianobactérias/fisiologia , Herbicidas/toxicidade , Microcistinas/metabolismo , Clorofila/análogos & derivados , Clorofila A , Cobre/toxicidade , Sulfato de Cobre/toxicidade , Cianobactérias/efeitos dos fármacos , Florida , Proliferação Nociva de Algas , Lagos/microbiologia , Microcystis , Água
11.
Ecotoxicol Environ Saf ; 207: 111265, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32920313

RESUMO

Aluminum (Al) toxicity is a major yield-limiting factor for crops in acidic soils. In this work, we have investigated the potential role of spermidine (Spd) on Al toxicity in rice chloroplasts. Exogenous Spd markedly reduced Al concentration and elevated other nutrient elements such as Mn, Mg, Fe, K, Ca, and Mo in chloroplasts of Al-treated plants. Meanwhile, Spd further activated arginine decarboxylase (ADC) activity of key enzyme in polyamine (PA) synthesis, and enhanced PA contents in chloroplasts. Spd application dramatically addressed Al-induced chlorophyll (Chl) losses, inhibited thylakoid membrane protein complexes degradation, especially photosystem II (PSII), and significantly depressed the accumulations of superoxide radical (O2·-), hydrogen peroxide (H2O2), and malondialdehyde (MDA) in chloroplasts. Spd addition activated antioxidant enzyme activities and decreased soluble sugar content in chloroplasts compared with Al treatment alone. Spd not only reversed the inhibition of photosynthesis-related gene transcript levels induced by Al toxicity, but diminished the increased expression of Chl catabolism-related genes. Furthermore, Chl fluorescence analysis showed that Spd protected PSII reaction centers and photosynthetic electron transport chain under Al stress, thus improving photosynthetic performance. These results suggest that PAs are involved in Al tolerance in rice chloroplasts and can effectively protect the integrity and function of photosynthetic apparatus, especially PSII, by mitigating oxidative damage induced by Al toxicity.


Assuntos
Alumínio/toxicidade , Complexo de Proteína do Fotossistema II/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Espermidina/farmacologia , Alumínio/metabolismo , Antioxidantes/metabolismo , Clorofila/metabolismo , Cloroplastos/efeitos dos fármacos , Peróxido de Hidrogênio/metabolismo , Malondialdeído/metabolismo , Fotossíntese/efeitos dos fármacos , Complexo de Proteína do Fotossistema II/metabolismo , Poliaminas/metabolismo , Espermidina/metabolismo
12.
Food Chem ; 339: 128057, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32947106

RESUMO

The effect of light exposure on sensory quality, health-promoting phytochemical contents, and antioxidant capacity in the lateral buds of baby mustard plants was investigated at ambient storage temperature (20 °C). The results showed that light exposure (36 µmol m-2 s-1) during post-harvest storage significantly prolonged shelf life (more than 1.75-fold), delayed the weight loss and the decrease of firmness. Light treatments also enhanced chlorophyll and carotenoid contents, and retarded declines in contents of soluble sugars, ascorbic acid, flavonoids and glucosinolates, as well as antioxidant capacity. The quality of baby mustard plants receiving 24 h daily light treatment was superior to those in plants receiving 12 h treatment and constant darkness at 20 °C. These findings indicate that light exposure, especially 24 h treatment, is an effective method of prolonging shelf life and maintaining sensory and nutritional qualities in baby mustard plants stored at ambient temperature.


Assuntos
Antioxidantes/análise , Armazenamento de Alimentos/métodos , Mostardeira/química , Compostos Fitoquímicos/análise , Antioxidantes/química , Ácido Ascórbico/análise , Carotenoides/análise , Clorofila/análise , Cor , Qualidade dos Alimentos , Glucosinolatos/análise , Luz , Valor Nutritivo , Temperatura
13.
Environ Pollut ; 270: 116288, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33352484

RESUMO

The particle size distribution (PSD) slope (ξ) can indicate the predominant particle size, material composition, and inherent optical properties (IOPs) of inland waters. However, few semi-analytical methods have been proposed for deriving ξ from the surface remote sensing reflectance due to the variable optical state of inland waters. A semi-analytical algorithm was developed for inland waters having a wide range of turbidity and ξ in this study. Application of the proposed model to Ocean and Land Color Instrument (OLCI) imagery of the water body resulted in several important observations: (1) the proposed algorithm (754 nm and 779 nm combination) was capable of retrieving ξ with R2 being 0.72 (p < 0.01, n = 60), and MAPE and RMSE being 4.37% and 0.22 (n = 30) respectively; (2) the ξ in HZL was lower in summer than other seasons during the period considered, this variation was driven by the phenological cycle of algae and the runoff caused by rainfall; (3) the band optimization proposed in this study is important for calculating the particle backscattering slope (η) and deriving ξ because it is feasible for both algae dominant and sediment governed turbid inland lakes. These observations help improve our understanding of the relationship between IOPs and ξ, which are affected by different bio-optic processes and algal phenology in the lake environment.


Assuntos
Clorofila , Lagos , Algoritmos , Clorofila/análise , Monitoramento Ambiental , Tamanho da Partícula , Água/análise
14.
J Environ Manage ; 279: 111766, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33310244

RESUMO

Algal blooms and the presence of cyanotoxins in surface water restrict the public from accessing lakes and beaches for drinking and recreational activities. An effort was taken in this on-site study to improve the surface water quality of a eutrophic lake, which has been under a swimming advisory for many years. A floating filtration unit with non-woven geotextiles as a sole filter media was tested for removing algae, nutrients, and suspended solids from overlying water under different lake conditions. Three non-woven geotextiles of different pore sizes were examined in different combinations and lake water quality was monitored for different physico-chemical, biological parameters. A YSI-EXO2 multiparameter probe was used for continuous online water quality monitoring during filtration. Depending on the initial water quality, excellent removal efficiency was observed as follows: 85-98% turbidity, 98-100% total suspended solids (TSS), 57-88% total phosphorus (TP), 33-66% chemical oxygen demand (COD) and 80-96% chlorophyll a (Chl. a.). The filtered lake water quality satisfied the norm set for oligotrophic lakes for TP and Chl. a. Results from this on-site study are very promising, showing the potential applicability of geotextile filtration as an ecologically attractive technique to improve the surface water quality of small aquatic bodies.


Assuntos
Lagos , Qualidade da Água , China , Clorofila/análise , Clorofila A , Monitoramento Ambiental , Eutrofização , Nitrogênio/análise , Fósforo/análise
15.
Food Chem ; 337: 127771, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32777564

RESUMO

Faveleira (Cnidoscolus quercifolius) is an emerging Brazilian plant, with seeds rich in edible oil. This study investigates physicochemical properties, chemical composition, thermal and oxidative stability, in vitro and in vivo toxicity, antioxidant, antinociceptive and anti-inflammatory activities of faveleira seed oil. It was observed that the oil has low acidity, value of peroxide, chlorophyll, carotenoids, ß-carotene and high concentrations of unsaturated fatty acids. In addition to presenting thermal and oxidative stability and high total phenolic content, with vanillin, eugenol and quercetin were predominating. The oil showed no toxicity in vitro and in vivo, and presented antioxidant, anti-inflammatory and antinociceptive activities. These findings provide relevant and appropriate conditions for processing of faveleira seed oil as functional food.


Assuntos
Euphorbiaceae/metabolismo , Óleos Vegetais/química , Analgésicos/química , Analgésicos/farmacologia , Analgésicos/uso terapêutico , Animais , Antioxidantes/química , Brasil , Carotenoides/análise , Sobrevivência Celular/efeitos dos fármacos , Clorofila/análise , Euphorbiaceae/química , Ácidos Graxos/análise , Masculino , Camundongos , Dor/induzido quimicamente , Dor/prevenção & controle , Fenóis/análise , Óleos Vegetais/farmacologia , Óleos Vegetais/uso terapêutico , Células RAW 264.7 , Sementes/química , Sementes/metabolismo
16.
Chemosphere ; 263: 128169, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33297138

RESUMO

A hydroponic study was conducted to determine the effects of single and/or combined application of different doses (0, 5 and 10 µM L-1) of abscisic acid (ABA) and 6-benzylaminopurine (BAP) on cobalt (Co) accumulation, morpho-physiological and antioxidative defense attributes of tomato (Solanum lycopersicum L.) exposed to severe Co stress (400 µM L-1). The single Co treatment (T1), prominently decreased tomato growth, relative water contents, photosynthetic pigments (chlorophyll a and chlorophyll b), whereas enhanced oxidative stress and Co accumulation in shoot and root tissues. Nonetheless, the supplementation of ABA and 6-BAP via nutrient media significantly (P < 0.05) enhanced plant biomass, root morphology and chlorophyll contents of tomato, compared to only Co treatment (T1). Moreover, the oxidative stress indicators such as malondialdehyde, proline and H2O2 contents were ameliorated through activation of enzymatic antioxidant activities i.e. ascorbate peroxidase, superoxide dismutase, catalase, and peroxidase, in growth modulator treatments in comparison to T1. The Co uptake, translocation (TF) and bioaccumulation factor (BAF) by shoot and root tissues of tomato were significantly reduced under all the treatments than that of T1. The supply of 6-BAP alone or in combination with ABA at 10 µM L-1 application (T7) rate was found the most effective to reduce Co accumulation in the roots and shoots by 48.4% and 70.2% respectively than T1 treatment. It can be concluded that two plant growth modulators could improve the stress tolerance by inhibition of Co uptake in tomato plants.


Assuntos
Antioxidantes , Lycopersicon esculentum , Ácido Abscísico , Compostos de Benzil , Clorofila , Clorofila A , Cobalto/toxicidade , Peróxido de Hidrogênio , Folhas de Planta , Purinas
17.
Ying Yong Sheng Tai Xue Bao ; 31(10): 3331-3339, 2020 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-33314822

RESUMO

The effects of seed size and drought stress on the growth and physiological characteristics of Quercus wutaishanica seedlings were investigated under shading conditions of a pot experiment in greenhouse. There were four treatments, including 80% field water content (FWC), 60% FWC, 40% FWC, and 20% FWC [CK, light drought stress (LDS), medium drought stress (MDS), and high drought stress (HDS), respectively]. The results showed that leaf area per plant, total dry mass, and root-shoot ratio of Q. wutaishanica seedlings regenerated from large seeds (3.05±0.38 g) were significantly higher than those from small seeds (1.46±0.27 g) in all four treatments. Shoot height, basal stem diameter, leaf number, specific leaf area, relative growth rate, and net assimilation rate of the seedlings from large seeds were higher than those of seedlings from small seeds under the treatments of LDS, MDS and HDS. Activities of peroxidase (POD), catalase (CAT), and superoxide dismutase (SOD) in large-seeded seedlings were higher than those of small-seeded seedlings under all treatments, while the contents of MDA, soluble protein, free proline, and total chlorophyll of large-seeded seedlings were higher than those of small-seeded seedlings only under some drought stress treatments. All growth parameters except the root-shoot ratio decreased with the increases of drought stress. The HDS treatment resulted in 19.4% and 20.0% decline in total dry mass of large- and small-seeded seedlings respectively, compared with those of CK. With increasing drought stress, the activities of POD, CAT, and SOD decreased after an initial increase. POD activity of large- and small-seeded seedling under MDS treatment was 126.7% and 142.1% higher than CK, while CAT was 170.0% and 151.9% higher than CK, respectively. However, the MDA content of seedlings from large and small seeds under HDS treatment was 86.5% and 68.9% higher than that of CK, respectively. The contents of soluble protein, free proline, and total chlorophyll rose at first and then fell with increasing drought stress, and soluble protein content in large- and small-seeded seedlings experienced MDS enhanced 320.7% and 352.7%, respectively. Those results indicated that large-seeded seedlings of Q. wutaishanica had stronger drought tolerance than small-seeded seedlings due to their growth and physiology advantages. Large-seeded seedlings with stronger resistance to drought stress should be applied to artificial regeneration of the degraded secondary Q. wutaishanica plantations.


Assuntos
Quercus , Plântula , Clorofila , Secas , Sementes , Estresse Fisiológico
18.
Ying Yong Sheng Tai Xue Bao ; 31(10): 3473-3479, 2020 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-33314837

RESUMO

Shading is one of the important strategies to protect seedlings of Paeonia lactiflora. The effects of shading treatments on seedling growth and mineral accumulation of Duolun P. lactiflora were investigated in a greenhouse experiment to provide guidance for P. lactiflora cultivation. One week after emergence, seedlings were treated with 20%, 40%, 60% or 80% shading for two months, with no-shading as the control (CK). The results showed that shading treatments significantly increased plant height by 19.9%, 31.1%, 52.9%, and 63.7%, respectively. However, shading significantly reduced the root mass ratio and root to shoot ratio by 21.5%, 23.6%, 29.2%, 41.8% and 40.6%, 44.0%, 50.9%, 63.2%, respectively. Moreover, 40%, 60% and 80% shading significantly increased specific leaf area by 77.0%, 84.1% and 65.2%, and significantly increased chlorophyll content by 92.3%, 128.7%, 98.1%, and increased carotenoid content by 86.9%, 113.1% and 90.5%, respectively. The treatments of 40%, 60%, and 80% shading significantly decreased root biomass by 61.4%, 74.3% and 78.6%, respectively. Compared with CK, 20%, 40% and 80% shading, the 60% shading treatment increased root phosphorus content by 245.7%, 65.9%, 40.5% and 10.3%, increased potassium content by 102.9%, 131.7%, 57.0%, 63.3% and magnesium content by 131.3%, 55.1%, 40.4%, 7.7%, respectively. 60% shading was an appropriate shading intensity for P. lactiflora seedling cultivation based on local conditions in Duolun.


Assuntos
Paeonia , Plântula , Clorofila , Minerais , Folhas de Planta
19.
Nat Commun ; 11(1): 6388, 2020 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-33319777

RESUMO

Evergreen conifers in boreal forests can survive extremely cold (freezing) temperatures during long dark winter and fully recover during summer. A phenomenon called "sustained quenching" putatively provides photoprotection and enables their survival, but its precise molecular and physiological mechanisms are not understood. To unveil them, here we have analyzed seasonal adjustment of the photosynthetic machinery of Scots pine (Pinus sylvestris) trees by monitoring multi-year changes in weather, chlorophyll fluorescence, chloroplast ultrastructure, and changes in pigment-protein composition. Analysis of Photosystem II and Photosystem I performance parameters indicate that highly dynamic structural and functional seasonal rearrangements of the photosynthetic apparatus occur. Although several mechanisms might contribute to 'sustained quenching' of winter/early spring pine needles, time-resolved fluorescence analysis shows that extreme down-regulation of photosystem II activity along with direct energy transfer from photosystem II to photosystem I play a major role. This mechanism is enabled by extensive thylakoid destacking allowing for the mixing of PSII with PSI complexes. These two linked phenomena play crucial roles in winter acclimation and protection.


Assuntos
Transferência de Energia , Fotossíntese/fisiologia , Complexo de Proteína do Fotossistema I/metabolismo , Complexo de Proteína do Fotossistema II/metabolismo , Pinus sylvestris/metabolismo , Aclimatação , Clorofila , Cloroplastos/metabolismo , Cloroplastos/ultraestrutura , Fluorescência , Cinética , Luz , Processos Fotoquímicos , Complexo de Proteína do Fotossistema I/química , Complexo de Proteína do Fotossistema II/química , Estações do Ano , Temperatura , Tilacoides/metabolismo , Fatores de Tempo , Árvores/metabolismo
20.
Ying Yong Sheng Tai Xue Bao ; 31(9): 3101-3110, 2020 Sep 15.
Artigo em Chinês | MEDLINE | ID: mdl-33345512

RESUMO

We examined the effects of biochar and effective mircoorganisms (EM) application on growth and photosynthetic characteristics of Sesbania cannabina in the Yellow River Delta, by a pot experiment with different EM treatments (without EM addition, EM-; with EM addition, EM+) and a gradient of biochar treatments (0, B0; 0.5%, B1; 1.5%, B2; 3%, B3; biochar weight/soil weight). The growth parameters, photosynthetic light response curve and chlorophyll fluorescence characteristics of S. cannabina were measured. The results showed that the EM+B3 treatment had the best effect among all the treatments. Compared with the EM-B0 treatment, the EM+B3 treatment increased height, stem diameter, and total biomass by 69.5%, 90.0% and 141.1%, respectively. Biochar and EM significantly improved photosynthetic capacity. Compared with the EM-B0 treatment, the EM+B3 treatment significantly enhanced the maximum light response of net photosynthetic rate, transpiration rate, water use efficiency, and stomatal conductance by 93.8%, 35.1%, 43.4%, and 34.8%, respectively. Biochar and EM improved the parameters of chlorophyll fluorescence. Compared with the EM-B0 treatment, the EM+B3 treatment significantly increased the potential photochemical efficiency, the actual photochemical efficiency, the apparent electron transport rate and the non-photochemical quenching coefficient by 25.8%, 31.5%, 37.2%, and 56.8%, respectively. The parameters of growth, photosynthesis and chlorophyll fluorescence increased with the increasing biochar under EM+ treatments, whereas the B3 treatment had negative effect under EM- treatments. The co-addition of EM and 3% biochar (EM+B3) could improve the photosynthetic capacity and chlorophyll fluorescence characteristics of S. cannabina, broaden light ecological amplitude, boost the water retention and drought resistance property, and promote the growth of S. cannabina.


Assuntos
Sesbania , Solo , Álcalis , Carvão Vegetal , China , Clorofila , Fluorescência , Fotossíntese , Folhas de Planta , Rios
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