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1.
J Photochem Photobiol B ; 203: 111761, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31896050

RESUMO

The combination of different colors from light-emitting diodes (LEDs) may influence growth and production of secondary metabolites in plants. In the present study, the effect of light quality on morphophysiology and content of 20-hydroxyecdysone (20E), a phytoecdysteroid, was evaluated in accessions of an endangered medicinal species, Pfaffia glomerata, grown in vitro. Two accessions (Ac22 and Ac43) were cultured in vitro under three different ratios of red (R) and blue (B) LEDs: (i) 1R:1B, (ii) 1R:3B, and (iii) 3R:1B. An equal ratio of red and blue light (1R:1B) increased biomass accumulation, anthocyanin content, and 20E production (by 30-40%). Moreover, 1R:1B treatment increased the size of vascular bundles and vessel elements, as well as strengthened xylem lignification and thickening of the cell wall of shoots. The 1R:3B treatment induced the highest photosynthetic and electron transport rates and enhanced the activity of oxidative stress-related enzymes. Total Chl content, Chl/Car ratio, and NPQ varied more by accession type than by light source. Spectral quality affected primary metabolism differently in each accession. Specifically, in Ac22 plants, fructose content was higher under 1R:1B and 1R:3B treatments, whereas starch accumulation was higher under 1R:3B, and sucrose under 3R:1B. In Ac43 plants, sugars were not influenced by light spectral quality, but starch content was higher under 3R:1B conditions. In conclusion, red and blue LEDs enhance biomass and 20E production in P. glomerata grown in vitro.


Assuntos
Amaranthaceae/efeitos da radiação , Ecdisterona/análise , Luz , Amaranthaceae/crescimento & desenvolvimento , Amaranthaceae/metabolismo , Antocianinas/análise , Biomassa , Carotenoides/análise , Catalase/metabolismo , Clorofila/análise , Cromatografia Líquida de Alta Pressão , Folhas de Planta/química , Proteínas de Plantas/metabolismo , Raízes de Plantas/química , Raízes de Plantas/crescimento & desenvolvimento , Caules de Planta/química , Plantas Medicinais/crescimento & desenvolvimento , Plantas Medicinais/metabolismo , Plantas Medicinais/efeitos da radiação , Amido/metabolismo , Superóxido Dismutase/metabolismo
2.
Plant Mol Biol ; 102(3): 323-337, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31900819

RESUMO

KEY MESSAGE: There is a link between PAP/SAL retrograde pathway, ethylene signaling and Fe metabolism in Arabidopsis. Nuclear gene expression is regulated by a diversity of retrograde signals that travel from organelles to the nucleus in a lineal or classical model. One such signal molecule is 3'-phosphoadenisine-5'-phosphate (PAP) and it's in vivo levels are regulated by SAL1/FRY1, a phosphatase enzyme located in chloroplast and mitochondria. This metabolite inhibits the action of a group of exorribonucleases which participate in post-transcriptional gene expression regulation. Transcriptome analysis of Arabidopsis thaliana mutant plants in PAP-SAL1 pathway revealed that the ferritin genes AtFER1, AtFER3, and AtFER4 are up-regulated. In this work we studied Fe metabolism in three different mutants of the PAP/SAL1 retrograde pathway. Mutant plants showed increased Fe accumulation in roots, shoots and seeds when grown in Fe-sufficient condition, and a constitutive activation of the Strategy I Fe uptake genes. As a consequence, they grew more vigorously than wild type plants in Fe-deficient medium. However, when mutant plants grown in Fe-deficient conditions were sprayed with Fe in their leaves, they were unable to deactivate root Fe uptake. Ethylene synthesis inhibition revert the constitutive Fe uptake phenotype. We propose that there is a link between PAP/SAL pathway, ethylene signaling and Fe metabolism.


Assuntos
Difosfato de Adenosina/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Ferro/metabolismo , Monoéster Fosfórico Hidrolases/metabolismo , Transdução de Sinais , Difosfato de Adenosina/genética , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Clorofila , Cloroplastos/metabolismo , Ferritinas/genética , Ferritinas/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas/genética , Homeostase , Mitocôndrias/metabolismo , Mutação , Monoéster Fosfórico Hidrolases/genética , Folhas de Planta/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo
3.
J Photochem Photobiol B ; 203: 111763, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31931382

RESUMO

Photodynamic therapy (PDT) is a clinical modality that allows the destruction of tumor cells and microorganisms by reactive oxygen species, formed by the combination of photosensitizer (PS), molecular oxygen and adequate wavelength light. This research, through a clean methodology that involves pressurized liquids extraction (PLE), obtained a highly antimicrobial extract of Tetragonia tetragonoides, which rich in chlorophylls as photosensitizers. The Chlorophylls-based extract (Cbe-PLE) presented pharmacological safety, through the maintenance of cellular viability. In addition, Cbe-PLE showed great efficacy against Staphylococcus aureus, with severe dose-dependent damage to the cell wall of the pathogen. The obtained product has a high potential for the development of photostimulated phytotherapic formulations for clinical applications in localized infections, as a complementary therapeutic alternative to antibiotics.


Assuntos
Aizoaceae/química , Extratos Vegetais/química , Aizoaceae/metabolismo , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Clorofila/química , Clorofila/farmacologia , Luz , Camundongos , Testes de Sensibilidade Microbiana , Nanoestruturas/química , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/farmacologia , Folhas de Planta/química , Folhas de Planta/metabolismo , Caules de Planta/química , Caules de Planta/metabolismo , Staphylococcus aureus/efeitos dos fármacos
4.
J Photochem Photobiol B ; 203: 111768, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31931383

RESUMO

In vitro callus cultures of Verbena officinalis L. were maintained on solid Murashige and Skoog medium, enriched with 1 mg dm-3 BA and 1 mg dm-3 IBA under LED lights (red, blue, red/blue 70%/30%), in darkness and under control fluorescent lamps. The measurements of 2 phenylpropanoid glycosides (verbascoside and isoverbascoside) and 23 phenolic acids were performed in methanolic extracts from the biomass collected after 2-, 3- and 4-week growth cycles using the HPLC-DAD method. The presence of verbascoside, isoverbascoside and additionaly 7 phenolic acids (protocatechuic, chlorogenic, vanillic, caffeic, ferulic, o-coumaric and m-coumaric acids) was confirmed in all extracts. Blue and red/blue lights stimulated the accumulation of verbascoside (max. of 6716 and 6023 mg 100 g-1 DW after a 4-week growth cycle) and isoverbascoside (max. 333 and 379 mg 100 g-1 DW also after 4 weeks). The maximum amounts of verbascoside and isoverbascoside were respectively 1.8- and 7.0-fold higher than under the control conditions. Phenolic acids were accumulated in different amounts, and the maximum total amounts ranged from 36 to 65 mg 100 g-1 DW. LED lights also stimulated their accumulation in comparison with darkness and control. The main phenolic acids included: m-coumaric acid (max. 39 mg 100 g-1 DW), ferulic acid (max. 12 mg 100 g-1 DW), and protocatechuic acid (max. 13 mg 100 g-1 DW). Additionally, the quantities of photosynthetic pigments (chlorophyll a, b and carotenoids) were estimated in acetonic extracts using spectrophotometry. Red/blue light stimulated the biosynthesis of pigments (max. total content 287 µg g-1 FW after 4-week growth cycles). This is the first study describing the effect of LED lights on the production of phenylpropanoid glycosides and phenolic acids in V. officinalis callus cultures. Very high amounts of verbascoside and isoverbascoside are interesting from a practical point of view.


Assuntos
Glucosídeos/metabolismo , Hidroxibenzoatos/metabolismo , Luz , Fenóis/metabolismo , Verbena/metabolismo , Biomassa , Carotenoides/análise , Clorofila/análise , Clorofila A/análise , Cromatografia Líquida de Alta Pressão , Glucosídeos/análise , Hidroxibenzoatos/análise , Fenóis/análise , Fotossíntese/efeitos da radiação , Análise de Componente Principal , Análise de Regressão , Espectrofotometria
5.
Nat Commun ; 11(1): 534, 2020 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-31988280

RESUMO

A disturbance of reactive oxygen species (ROS) homeostasis may cause the pathogenesis of many diseases. Inspired by natural photosynthesis, this work proposes a photo-driven H2-evolving liposomal nanoplatform (Lip NP) that comprises an upconversion nanoparticle (UCNP) that is conjugated with gold nanoparticles (AuNPs) via a ROS-responsive linker, which is encapsulated inside the liposomal system in which the lipid bilayer embeds chlorophyll a (Chla). The UCNP functions as a transducer, converting NIR light into upconversion luminescence for simultaneous imaging and therapy in situ. Functioning as light-harvesting antennas, AuNPs are used to detect the local concentration of ROS for FRET biosensing, while the Chla activates the photosynthesis of H2 gas to scavenge local excess ROS. The results thus obtained indicate the potential of using the Lip NPs in the analysis of biological tissues, restoring their ROS homeostasis, possibly preventing the initiation and progression of diseases.


Assuntos
Clorofila/metabolismo , Hidrogênio/metabolismo , Lipossomos/metabolismo , Nanopartículas Metálicas/química , Fotossíntese , Espécies Reativas de Oxigênio/metabolismo , Técnicas Biossensoriais , Ouro , Nanoestruturas
6.
Water Res ; 171: 115403, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31901508

RESUMO

Remote sensing reflectance (Rrs) values measured by satellite sensors involve large amounts of uncertainty leading to non-negligible noise in remote Chlorophyll-a (Chl-a) concentration estimation. This work distinguished between two main stages in the case of estimating distributions of Chl-a within the Gulf of St. Lawrence (Canada). At the model building stage, the retrieval algorithm used both in-situ Chl-a measurements and the corresponding Moderate Resolution Imaging Spectroradiometer (MODIS) L2-level data estimated Rrs at 412, 443, 469, 488, 531, 547, 555, 645, 667, 678 nm at a 1 km spatial resolution during 2004-2013. Through the training and validation of various models and Rrs combinations of the considered eight techniques (including support vector regression, artificial neural networks, gradient boosting machine, random forests, standard CI-OC3M, multiple linear regression, generalized addictive regression, principal component regression), the support vector regression (SVR) technique was shown to have the best performance in Chl-a concentration estimation using Rrs at 412, 443, 488, 531 and 678 nm. The accuracy indicators for both the training (850) and the validation (213) datasets were found to be very good to excellent (e.g., the R2 value varied between 0.7058 and 0.9068). At the space-time estimation stage, this work took a step forward by using the Bayesian maximum entropy (BME) theory to further process the SVR estimated Chl-a concentrations by incorporating the inherent spatiotemporal dependency of physical Chl-a distribution. A 56% improvement was achieved in the reduction of the mean uncertainty of the validation data decreased considerably (from 1.2222 to 0.5322 mg/m3). Then, this novel BME/SVR framework was employed to estimate the daily Chl-a concentrations in the Gulf of St. Lawrence during Jan 1-Dec 31 of 2017 (1 km spatial resolution). The results showed that the daily mean Chl-a concentration varied from 1.6630 to 3.3431 mg/m3, and that the daily mean Chl-a uncertainty reduction of the composite BME/SVR vs. the SVR estimation had a maximum reduction value of 1.0082 and an average reduction value of 0.6173 mg/m3. The monthly spatial Chl-a distribution covariances showed that the highest Chl-a concentration variability occurred during November and that the spatiotemporal Chl-a concentration pattern changed a lot during the period August to November. In conclusion, the proposed BME/SVR was shown to be a promising remote Chl-a retrieval approach that exhibited a significant ability in reducing the non-negligible uncertainty and improving the accuracy of remote sensing Chl-a concentration estimates.


Assuntos
Clorofila A , Tecnologia de Sensoriamento Remoto , Teorema de Bayes , Canadá , Clorofila , Monitoramento Ambiental , Incerteza
7.
Water Res ; 171: 115441, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31927090

RESUMO

This study is an analysis of relationships between microalgae (measured as chlorophyll a) and the fecal indicator bacteria enterococci. Microalgae blooms and enterococci exceedances have been occurring in Florida's recreational waterways for years. More recently, this has become a management concern as microalgae blooms have been attributed to potentially toxic cyanobacteria, and enterococci exceedances link to human infection/illness. Since both the microalgal blooms and bacterial exceedances occur in regions that receive managed freshwater releases from Lake Okeechobee, we hypothesized that both the blooms and exceedances are related to excess nutrients from the lake. Two experimental sites, on Lake Okeechobee and the St. Lucie River (downstream of the lake), plus a control site on the Loxahatchee River (which does not receive lake flow) were evaluated. The hypothesis was evaluated through three study components: 1) analysis of available long-term data from local environmental databases, 2) a year-long monthly sampling and analysis of chlorophyll a, enterococci, nutrients, and physical-chemical data, and 3) microcosm experiments with altered water/sediment conditions. Results support the hypothesis that excess nutrients play a role in both chlorophyll a and enterococci levels. For the St. Lucie River, analyses indicate that chlorophyll a correlated significantly with total Kjeldahl nitrogen (TKN) (R2 = 0.30, p = 0.008) and the strongest model for enterococci included nitrate-nitrite, TKN, total phosphorus, orthophosphorus, and turbidity in our long-term analysis (n = 39, R2 = 0.83, p ≤ 0.001). The microcosm results indicated that chlorophyll a and enterococci only persisted for 36 h in water from all sources, and that sediments from Lake Okeechobee may have allowed for sustained levels of chlorophyll a and enterococci levels. Overall similarities were observed in chlorophyll a and enterococci relationships with nutrient concentrations regardless of a Lake Okeechobee connection, as underscored by a study of flow out of the lake and downstream areas. This suggests that both nutrient-rich lake water and untreated surface water runoff contribute to microalgae blooms and enterococci exceedances in southeast Florida.


Assuntos
Lagos , Microalgas , Proliferação de Células , Clorofila , Clorofila A , Enterococcus , Monitoramento Ambiental , Eutrofização , Florida , Nitrogênio , Fósforo
8.
Bioresour Technol ; 301: 122743, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31945684

RESUMO

The aim of this work was to investigate the potential of PEF technology for green extraction of microalgal pigments and lipids from fresh Chlorella sorokiniana suspensions. Efficiencies of PEF treatment and different solvent systems application to C.sorokiniana were compared to efficiencies of untreated biomass extraction. Differences in chlorophyll extraction of untreated and PEF treated C.sorokiniana were only seen at short extraction times. Beneficial PEF-effect was minimised for long-time extractions of larger algae quantities where yields aligned. Extraction attempts on C. sorokiniana lipids did not show increased extractability after PEF treatment, which underlined the statement of PEF representing a rather ineffective disruption method for microalgae holding rigid cell walls.


Assuntos
Chlorella , Microalgas , Biomassa , Clorofila , Eletricidade
9.
J Environ Manage ; 258: 109989, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31929079

RESUMO

The chlorophyll-breakdown to pheophorbide is determined by biotic factors such as grazing (via chlorophyllide) or senescence (via pheophytin). So far, much of the information on chlorophyll-breakdown is available from sediments, but information from the water column is limited. This study addressed chlorophyll-breakdown-pathways (Chl-BP) on a seasonal basis from eight major ports (18-30 stations/port) representing freshwater, estuarine, and marine ecosystems. The distribution of chlorophyll and its breakdown fractions (pheophytin, pheophorbide) exhibited distinct spatial and seasonal variations. Fresh-water (except Haldia-port) and estuarine ports are characterized by high-biomass, high-pheophytin, and low-pheophorbide, whereas marine-ports by low-biomass (except Mangalore-port), low-pheophytin, and high-pheophorbide. Pheophytin and pheophorbide distribution were biomass independent and dependent, respectively. The pheophorbide: pheophytin ratio indicated a potential proxy for determining the dominant breakdown pathway, i.e., herbivory dominant (>1) or not dominant (<1). However, CHl-BP is taxa-specific and grazer's feeding habits. The ratios exhibited apparent differences between different ecosystems, i.e., the higher ratios in marine (up to 11.2) followed by estuarine (up to 0.9) and freshwater (up to 0.4; except Haldia) systems. The diatoms (preferred grazer diet) contribution to total phytoplankton was more in marine followed by estuarine and freshwater systems. The low and high ratios suggested the prevalence of chlorophyll-breakdown via senescence and grazing mode, respectively. We proposed that such scaling will have implications in the ballast water management - BWM (ballast tank conditions (eg. dark) during voyages, post-voyage discharge - including treated water using approved BWM systems, and the nature of ports, potential discharge point) and algal bloom research (e.g. understanding fate and in control measures).


Assuntos
Clorofila , Fitoplâncton , Ecossistema , Eutrofização , Água Doce
10.
Oecologia ; 192(1): 13-27, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31773314

RESUMO

Autumn canopy phenological transitions are increasing in length as a consequence of climate change. Here, we assess how well hyperspectral indices in the visible and near-infrared (NIR) wavelengths predict nitrogen (N) concentrations in lower-canopy leaves in the autumn phenological transition as they are generally understudied in leaf trait research. Using a Bayesian framework, we tested how well published indices are able to predict N concentrations in Fagus grandifolia Ehrh., Liriodendron tulipifera L., and Betula lenta L. from mid-summer through senescence, and how related the indices are to autumn phenological change. No indices were able to determine a trend in differences in N in mid-summer leaves. Indices that included wavelengths in the green and NIR ranges were the first indices able to detect a trend and had among the highest correlations with N concentration in both the last green collection and the senescing collection. Models were unique when indices were fit to data from different phenophases. Indices that focused on only the red edge (i.e., the sharp increase in reflectance between the red and NIR wavelengths) had the strongest explanatory power across the autumn phenological transition, but had less explanatory power for individual collections. These indices, as well as those that have been correlated with chlorophyll (CCI) and carotenoids (PRI), were the strongest descriptors of autumn progression. This study provides insights on challenges and capabilities to monitor a leaf's N concentration throughout and across canopy senescence.


Assuntos
Fagus , Teorema de Bayes , Clorofila , Nitrogênio , Folhas de Planta , Estações do Ano
11.
J Photochem Photobiol B ; 202: 111726, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31816516

RESUMO

The objective of the study was to investigate the effects of growth-stage specific lighting for the physiological homeostasis of red leaf lettuce (Lactuca sativa L. cv. Red Cos), by measuring the productivity of photosynthesis and primary metabolism. In the experiments, the main photosynthetic photon flux consisted of red (R) and blue (B) light, supplemented with blue, green (G) or UV-A wavelengths. Decrease of fructose, accompanied by significant decrease of stomatal conductance (gs), the ratio of intracellular to ambient CO2 concentration (Ci/Ca), photosynthetic rate (Pr), light adapted actual quantum yield of PSII photochemistry (ΦPSII), biomass formation and significant increase of transpiration rate (Tr) suggest that supplemental UV-A during maturity stage, after supplemental green irradiation during seedling stage (BRG to BRUV) was the least favourable condition for red leaf lettuce. However, constant irradiation with supplemental green (BRG) or supplemental green irradiation after increased blue exposure (B↑R to BRG) resulted in significant increase of Pr, gs, Ci/Ca, and light use efficiency(LUE), and decrease of Tr and Water use efficiency (WUE). Significant increase of leaf area was observed under supplemental green in both seedlings (BR; BRG) and matured plants (B↑R to BRG). Significant increase of specific leaf area was found under supplemental green (BRG) for seedlings and under increased blue (B↑R) for matured plants. Accordingly, the most favourable growth-stage specific lighting spectrum strategy for red leaf lettuce, based on photosynthetic and primary metabolite response, is supplemental green irradiation after increased blue exposure (B↑R to BRG), whereas, the most favourable condition for seedlings is BRG. According to the PCA correlation matrix, associations among the measured data indicate that WUE negatively correlated with gs and Ci/Ca, while LUE positively correlated with gs and Pr. However, weak correlations between ФPSII, LUE and photochemical reflectance index (PRI) suggest that selected light conditions were not optimal for red leaf lettuce.


Assuntos
Alface/efeitos da radiação , Luz , Clorofila/química , Análise por Conglomerados , Gases/química , Gases/metabolismo , Alface/crescimento & desenvolvimento , Fotossíntese/efeitos da radiação , Folhas de Planta/química , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/efeitos da radiação , Análise de Componente Principal , Teoria Quântica , Raios Ultravioleta
12.
Food Chem Toxicol ; 135: 110975, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31747619

RESUMO

This paper presents innovative packaging materials made of environmentally friendly biodegradable polymers (polylactide and polyhydroxybutyrate) with the addition of natural colorants commonly used in the food industry. Colorants fulfilled the role of indicator, changing colour under the influence of external factors, and gave the materials the characteristics of intelligent packaging, where colour changes indicated the life time of the materials. The paper gives the mechanical and thermal properties of the materials obtained, and describes changes in the colour of the samples under the influence of thermooxidation, UV and weathering, as well as the biodegradability of the materials. The packaging materials presented are in line with current trends in the packaging market and legal requirements. The samples, in addition to the basic functions of packaging materials, are pro-ecological and fully biodegradable new generation materials.


Assuntos
Plásticos Biodegradáveis/química , Compostos Cromogênicos/química , Embalagem de Alimentos , /química , Plásticos Biodegradáveis/metabolismo , Chaetomium/metabolismo , Clorofila/química , Curcumina/química , Luteína/química , Fungos Mitospóricos/metabolismo , Oxirredução , Poliésteres/química , Poliésteres/metabolismo , Temperatura Ambiente , beta Caroteno/química
13.
J Photochem Photobiol B ; 202: 111638, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31733613

RESUMO

The present study investigates the phycoremediation potentials of two microalgal consortia (MAC1 and MAC2) for treating sewage water and producing biomass with high lipid, protein and chlorophyll contents. During the study, the microalgal strains were tested for lipid enhancement, biomass production and contaminant removal from wastewater. The microalgal consortia showed prolific growth in wastewater with 75% dilution and accumulated higher lipid content of 31.33% dry cell weight in MAC1. The maximum biomass (50% diluted wastewater) for both the consortia was 1.53 and 1.04 gL-1. Total chlorophyll (19.17-25.17 µg mL-1) and protein contents (0.12-0.16 mg mL-1) for both the consortia were found to be maximum in 75 WW. MAC1 was capable of removing 86.27% of total organic carbon and 87.6% of chemical oxygen demand. Approximately, 94% of nitrate and phosphate contents were removed from the initial contents of wastewater. Heavy metal removal efficiency was also found to be better and showed 85.06% Cu, 75.2% Cr, 98.2% Pb, and 99.6% Cd removal by the algal consortia. Pyrolytic decomposition of algal consortia was observed using thermogravimetric analysis. The stepwise decomposition of algae indicated distinct losses of functional groups. The gas chromatography-mass spectrometric analysis revealed the majority of saturated fatty acids followed by monounsaturated and polyunsaturated fatty acids. Thus, the present study proved that both the consortia show tremendous potential for the treatment of domestic wastewaters with successive lipid enhancement for biodiesel production.


Assuntos
Biocombustíveis/análise , Ácidos Graxos/metabolismo , Microalgas/crescimento & desenvolvimento , Eliminação de Resíduos Líquidos/métodos , Proteínas de Algas/metabolismo , Biomassa , Clorofila/análise , Ácidos Graxos/análise , Cromatografia Gasosa-Espectrometria de Massas , Metais Pesados/química , Metais Pesados/metabolismo , Microalgas/metabolismo
14.
J Photochem Photobiol B ; 202: 111678, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31734433

RESUMO

Potted herbs such as basil are in high year-round demand in Central Europe. To ensure good quality in winter, artificial light is required. Many horticulturists, who want to replace their high-pressure­sodium (HPS) lamps with light-emitting diodes (LEDs) to save electricity energy, struggle with high investment costs. In addition, switching to LEDs can overwhelm many smaller horticultural enterprises since there is a requirement of adjusting individual light recipes and furthermore cultivation problems can occur due to the lack of infrared radiation. In this study, the influence of light from microwave plasma lamps (MPL), acting as alternative light sources, on secondary metabolites and morphology of basil plants (Ocimum basilicum L.) was tested. Basil plants were grown in a climate chamber with MPL with two different light bulbs emitting either artificial sunlight (AS) or broad white light with increased blue and green light content (sulfur plasma light; SPL). The effect of these new lamp types was compared to standard commercial HPS lamps. In addition to morphological parameters such as height, internode length and fresh weight, plant secondary metabolites were examined. Essential oils and monoterpenes were quantified by GC-MS analysis, whereby phenolic compounds were analyzed calorimetrically. Elongation growth and biomass production was increased under the AS spectrum in comparison to HPS-grown plants. Increased stem elongation was attributed to a higher content of far-red light in the AS spectrum. Furthermore, basil plants grown under the AS spectrum contained the highest total phenolic and total flavonoid content compared to plants grown under the SPL and HPS lamps, probably due to the higher content of UV-A radiation. The lowest content of phenolic compounds was observed when HPS light was used, which was assumed to be caused by a low blue light content in the emission spectrum. An impact of the different light spectra on essential oil composition was determined. A significantly increased content of linalool was found in basil leaves developed under both tested MPL spectra compared to HPS-grown plants. The total yield of the four major essential oils was lowest under HPS treatment.


Assuntos
Luz , Ocimum basilicum/química , Compostos Fitoquímicos/química , Gases em Plasma/química , Biomassa , Clorofila/análise , Flavonoides/análise , Cromatografia Gasosa-Espectrometria de Massas , Micro-Ondas , Ocimum basilicum/crescimento & desenvolvimento , Ocimum basilicum/metabolismo , Óleos Voláteis/análise , Fenóis/análise , Compostos Fitoquímicos/análise , Folhas de Planta/química , Folhas de Planta/metabolismo , Análise de Componente Principal
15.
Water Environ Res ; 92(1): 26-34, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31424121

RESUMO

Dilution with low-nutrient Columbia River Water (CRW) has markedly improved Moses Lake quality for 42 years. There were two phases of CRW volume input, which proportionately lowered total phosphorus (TP). Initially, spring-summer inputs averaged 130 × 106 m3 during 1977-1988 reducing average TP from 152 to 65 µg/L in half the lake proximal to the inputs. That input represented 1.5 volumes of that half-lake volume. Inputs doubled through the mid-1990s, and nearly 2.5 times since 2000, decreasing TP to a 18-year average of 24 µg/L. Chlorophyll a (chl) decreased further from 18 µg/L during the early dilution years to about 6 µg/L as TP declined. Cyanobacteria biovolume declined to 57% of total biovolume during 1977-1988 from 98% before dilution. Less (65%) CRW water since 2016 led to higher TP (41 µg/L) and chl (18 µg/L) in 2018, while cyanobacteria averaged 87% of total biovolume. More TP and cyanobacteria in 2018 are attributed to more internal TP loading. Increased N:P ratios have possibly given more advantage to the non-N-fixing cyanobacteria Microcystis, which comprised 82% and 74% of maximum cyanobacteria biovolume in 2017 and 2018. PRACTITIONER POINTS: Lake total phosphorus (TP) was reduced 57% in the 1970s-1980s by adding large volumes of low-nutrient Columbia River water (CRW). Total P was further reduced by 65% since 2000 by more than doubling the earlier CRW input to an average spring-summer concentration of 24 µg/L. Less (65%) CRW during 2017-2018 led to higher lake TP (41 µg/L) and a worse cyanobacteria bloom in 2018. Microcystis, an non-nitrogen fixer, was the dominant cyanobacteria in 2017-2018 likely related to higher N:P ratios.


Assuntos
Lagos , Fósforo , China , Clorofila , Clorofila A , Monitoramento Ambiental , Eutrofização
16.
Food Chem ; 309: 125763, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-31787393

RESUMO

The study was conducted to confirm the effects of selenium biofortification on the bioactive compounds and antioxidant activity of wheat microgreen extract. The microgreens were cultivated in the DFT hydroponic system with different concentrations of Se (0 [control], 0.125, 0.25, 0.50, and 1.00 mg/L from sodium selenite) in a growth chamber by controlling temperature (25/20 °C, day/night), light (12 h light/dark; intensity 150 µmol‧m-2‧s-1 with white fluorescence lamp), and humidity (60%) for 10 days. Se biofortification increased the germination rate and decreased microgreen length and yield. Chlorophyll and carotenoid levels increased in the Se-biofortified microgreen extract. Bioactive compounds such as phenolics, flavonoids, vitamin C, and anthocyanin significantly increased in 0.25-0.50 mg/L of Se-biofortified microgreen extracts. Antioxidant (ABTS, DPPH, NSA and SOD-like) activity also increased at moderate levels (0.25-0.50 mg/L) of Se biofortification. Therefore, Se biofortification may be useful for the industrial manufacture of new products from wheat microgreen extract.


Assuntos
Antioxidantes/química , Extratos Vegetais/química , Triticum/química , Ácido Ascórbico/análise , Biofortificação/métodos , Carotenoides/análise , Clorofila/análise , Flavonoides/análise , Germinação/efeitos dos fármacos , Fenóis/análise , Selenito de Sódio/farmacologia , Espectrofotometria Ultravioleta , Triticum/crescimento & desenvolvimento , Triticum/metabolismo , Regulação para Cima/efeitos dos fármacos
17.
Chemosphere ; 240: 124856, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31568945

RESUMO

The differential mechanisms of CdS QDs (Quantum Dots) and Cd ion toxicity to Arabidopsis thaliana (L.) Heynh were investigated. Plants were exposed to 40 and 60 mg L-1 for CdS QDs and 76.9 and 115.2 mg L-1 CdSO4·7H2O and toxicity was evaluated at 5, 20, 35 (T5, T20, T35) days after exposure. Oxidative stress upon exposure was evaluated by biochemical essays targeting non-enzymatic oxidative stress physiological parameters, including respiration efficiency, total chlorophylls, carotenoids, ABTS and DPPH radicals reduction, total phenolics, GSH redox state, lipid peroxidation. Total Cd in plants was measured with AAS. Root and leaf morphology and element content were assessed in vivo utilizing low-vacuum Environmental Scanning Electron Microscopy (ESEM) with X-ray microanalysis (EDX). This integrated approach allowed identification of unique nanoscale CdS QDs toxicity to the plants that was distinct from CdSO4 exposure. The analyses highlighted that CdS QDs and Cd ions effects are modulated by the developmental stage of the plant, starting from T20 till T35 the plant development was modulated by the treatments, in particular CdS QDs induced early flowering. Both treatments induced Fe accumulation in roots, but at different intensities, while CdS QDs was associated with Mn increase into plant leaf. CdSO4 elicited higher levels of oxidative stress compared with QDs, especially the former treatment caused more intense respiration damages and reduction in chlorophyll and carotenoids than the latter. The two types of treatments impact differently on root and leaf morphology.


Assuntos
Arabidopsis/efeitos dos fármacos , Arabidopsis/fisiologia , Compostos de Cádmio/toxicidade , Pontos Quânticos/toxicidade , Sulfetos/toxicidade , Cádmio/farmacocinética , Cádmio/toxicidade , Clorofila/metabolismo , Microanálise por Sonda Eletrônica , Peroxidação de Lipídeos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Folhas de Planta/efeitos dos fármacos , Raízes de Plantas , Pontos Quânticos/química
18.
Food Chem ; 306: 125300, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31562927

RESUMO

Chlorophyll is a valuable bioactive compound, which is used as a natural food coloring agent and a photosensitizer for photodynamic therapy because of its antioxidant properties, antimutagenic ability, and near-infrared fluorescence. However, chlorophyll is unstable when it comes to retaining its antioxidant activity, when exposed to oxygen, high temperature, or light environments. To enhance the stability of chlorophyll, a polymer encapsulation method was proposed. Polycaprolactone (PCL) was employed to encapsulate the chlorophyll, and the particles size of the composites was controlled through droplet microfluidics. The composites (chlorophyll-encapsulated PCL particles) were characterized through UV-VIS spectrometry, SEM, optical microscopy, and light exposure. The particles were spherical, with diameters adjustable from 68 to 247 µm. Additionally, the chlorophyll-encapsulated PCL particles exhibited considerably prolonged chlorophyll stability. The solid microparticle is more convenient for storage and transportation, and have great potential for application in the food industry.


Assuntos
Clorofila/química , Poliésteres/química , Microfluídica/métodos , Tamanho da Partícula
19.
Food Chem ; 308: 125707, 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-31669943

RESUMO

The ripening of the apple (Malus × domestica Borkh.) fruit is regulated by the phytohormone ethylene, where degreening is an important physiological metabolism caused by chlorophyll (Chl) degradation. However, to date, research on how ethylene affects the Chl degradation pathway of apple peel during ripening remains scarce. In this study, the effects of ethylene on the expression of Chl catabolic genes (CCGs) of apple peel during ripening were studied by treating harvested commercial mature apples with 0.5 µL L-1 1-methylcyclopropene (1-MCP). The results showed that 1-MCP treatment led to a delayed climacteric peak of respiration and ethylene production, exhibiting higher Chl content and hue angle (H˚) compared to untreated fruit during ripening. Lower quantities of pheophorbide a oxygenase (PAO), pheophytinase (PPH) and red Chl catabolite reductase (RCCR) were also observed in peel tissues under 1-MCP treatment during ripening. Further study with quantitative real-time polymerase chain reaction (qPCR) revealed that the expression of CCGs, except for MdNYE1a, increased atdifferentdegrees upon ripening. Meanwhile, the apples treated with 1-MCP presented a downregulated expression of MdRCCR2, MdNYC1, MdNYC3 and MdNOL2 and a fluctuating expression of MdNYE1a, MdPPH1, MdPAO6, MdPAO8 and MdHCAR compared with the controls during ripening. Our results indicated the regulatory role of ethylene in the Chl degradation pathway of apple peel during ripening.


Assuntos
Clorofila/metabolismo , Ciclopropanos/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Malus/metabolismo , Reguladores de Crescimento de Planta/farmacologia , Etilenos/metabolismo , Armazenamento de Alimentos , Frutas/efeitos dos fármacos , Frutas/metabolismo , Malus/efeitos dos fármacos , Proteínas de Plantas/metabolismo
20.
Sci Total Environ ; 699: 134402, 2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-31683210

RESUMO

Ground-level ozone (O3) is an important phytotoxic air pollutant in China. In order to compare the sensitivity of common poplar clones to O3 in China and explore the possible mechanism, five poplar clones, clone DQ (Populus cathayana), clone 84 K (P. alba × P. glandulosa), clone WQ156 (P. deltoids × P. cathayana), clone 546 (P. deltoides cv. '55/56' × P. deltoides cv. 'Imperial') and clone 107 (P. euramericana cv. '74/76') were exposed to four O3 treatments. According to the date of the initial visible O3 symptom and the slopes of O3 exposure-response relationships with the relative light-saturated rate of CO2 assimilation, we found that clone DQ and clone 546 were the most sensitive to O3, clone 84 K and clone WQ156 were the less sensitive, and clone 107 was the most tolerant, which could provide a basis to select O3 tolerant clones for poplar planting at areas with serious O3 pollution. Elevated O3 significantly reduced photosynthetic parameters, total phenols content, potential antioxidant capacity, leaf mass per area and biomass of five poplar clones, and there were significant interactions between O3 and clones for most photosynthetic parameters. Elevated O3 also significantly increased malondialdehyde content and total ascorbate content. The responses of total antioxidant capacity for poplar clones to elevated O3 were different, as indicated by the increase for clone 107 and reduction for other clones under elevated O3 treatment. Our results on the sensitivity of different poplar clones to O3 are not related to leaf stomatal conductance, leaf constitutive antioxidant levels or leaf morphology of plant grown in clean air. The possible reason is little difference in leaf traits among clones within close species, suggesting that more properties of plants should be considered for exploring the sensitivity mechanism of close species, such as mesophyll conductance, antioxidant enzyme activity and apoplastic antioxidants.


Assuntos
Poluentes Atmosféricos/toxicidade , Ozônio/toxicidade , Estômatos de Plantas/fisiologia , Populus/fisiologia , Antioxidantes , China , Clorofila/metabolismo , Fotossíntese , Folhas de Planta
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