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1.
Int J Mol Sci ; 22(15)2021 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-34360584

RESUMO

Trichostatin A (TSA) is a representative histone deacetylase (HDAC) inhibitor that modulates epigenetic gene expression by regulation of chromatin remodeling in cells. To investigate whether the regulation of chromatin de-condensation by TSA can affect the increase in the efficiency of Cas9 protein-gRNA ribonucleoprotein (RNP) indel formation from plant cells, genome editing efficiency using lettuce and tobacco protoplasts was examined after several concentrations of TSA treatments (0, 0.1, 1 and 10 µM). RNP delivery from protoplasts was conducted by conventional polyethylene glycol (PEG) transfection protocols. Interestingly, the indel frequency of the SOC1 gene from TSA treatments was about 3.3 to 3.8 times higher than DMSO treatment in lettuce protoplasts. The TSA-mediated increase of indel frequency of the SOC1 gene in lettuce protoplasts occurred in a concentration-dependent manner, although there was not much difference. Similar to lettuce, TSA also increased the indel frequency by 1.5 to 1.8 times in a concentration-dependent manner during PDS genome editing using tobacco protoplasts. The MNase test clearly showed that chromatin accessibility with TSA treatments was higher than that of DMSO treatment. Additionally, TSA treatment significantly increased the level of histone H3 and H4 acetylation from lettuce protoplasts. The qRT-PCR analysis showed that expression of cell division-related genes (LsCYCD1-1, LsCYCD3-2, LsCYCD6-1, and LsCYCU4-1) was increased by TSA treatment. These findings could contribute to increasing the efficiency of CRISPR/Cas9-mediated genome editing. Furthermore, this could be applied for the development of useful genome-edited crops using the CRISPR/Cas9 system with plant protoplasts.


Assuntos
Sistemas CRISPR-Cas , Edição de Genes/métodos , Ácidos Hidroxâmicos/farmacologia , Alface/metabolismo , Proteínas de Plantas/metabolismo , Protoplastos/metabolismo , Tabaco/metabolismo , Divisão Celular , Genoma de Planta , Alface/efeitos dos fármacos , Alface/genética , Alface/crescimento & desenvolvimento , Células Vegetais , Proteínas de Plantas/antagonistas & inibidores , Proteínas de Plantas/genética , Inibidores da Síntese de Proteínas/farmacologia , Protoplastos/efeitos dos fármacos , Tabaco/efeitos dos fármacos , Tabaco/genética , Tabaco/crescimento & desenvolvimento
2.
Molecules ; 26(14)2021 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-34299471

RESUMO

Phenylphenalenones, metabolites found in Schiekia timida (Haemodoraceae), are a class of specialized metabolites with many biological activities, being phytoalexins in banana plants. In the constant search to solve the problem of glyphosate and to avoid resistance to commercial herbicides, this work aimed to investigate the phytotoxic effect of the methanolic extract of S. timida seeds. The chemical composition of the seed extract was directly investigated by NMR and UPLC-QToF MS and the pre- and post-emergence phytotoxic effect on a eudicotyledonous model (Lactuca sativa) and a monocotyledonous model (Allium cepa) was evaluated through germination and seedling growth tests. Three concentrations of the extract (0.25, 0.50, and 1.00 mg/mL) were prepared, and four replicates for each of them were analyzed. Three major phenylphenalenones were identified by NMR spectroscopy: 4-hydroxy-anigorufone, methoxyanigorufone, and anigorufone, two of those reported for the first time in S. timida. The presence of seven other phenylphenalenones was suggested by the LC-MS analyses. The phenylphenalenone mixture did not affect the germination rate, but impaired radicle and hypocotyl growth on both models. The effect in the monocotyledonous model was statistically similar to glyphosate in the lowest concentration (0.25 mg/mL). Therefore, although more research on this topic is required to probe this first report, this investigation suggests for the first time that phenylphenalenone compounds may be post-emergence herbicides.


Assuntos
Alface/crescimento & desenvolvimento , Musa/química , Cebolas/crescimento & desenvolvimento , Fenalenos/toxicidade , Extratos Vegetais/toxicidade , Sementes/química , Germinação , Alface/efeitos dos fármacos , Cebolas/efeitos dos fármacos , Toxinas Biológicas/toxicidade
3.
Biomolecules ; 11(6)2021 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-34205142

RESUMO

Lettuce (Lactuca sativa) was grown using a foliar spray with whey protein hydrolysate (WPH) as opposed to normal nitrate fertilization. Lettuce juice was prepared from lettuce cultivated without any fertilization, nitrate fertilization, or WPH. Sixty weaned, 4-week-old male V-line rabbits with an average 455 ± 6 g body weight were randomly divided into 4 groups (n = 15) and administered different lettuce juices. Rabbits administered WPH-fertilized lettuce showed significantly higher (n = 5, p < 0.05) body weight and carcass weight than those receiving nitrate-fertilized lettuce. Rabbits administered nitrate-fertilized lettuce were associated with significantly (p < 0.05) higher levels of liver enzyme activities (AST, ALT, and ALP), bilirubin (total, direct, and indirect), and kidney biomarkers (creatinine, urea, and uric acid). Rabbits administered WPH-fertilized lettuce avoided such increases and exhibited normal levels of serum proteins. Rabbits administered nitrate-fertilized lettuce manifested significantly (p < 0.05) lower RBCs and Hb levels than that of the other groups, while those receiving WPH-fertilized lettuce showed the highest levels. Liver and kidney sections of rabbits receiving WPH-fertilized lettuce witnessed the absence of the histopathological changes induced by feeding on nitrate-fertilized lettuce and produced higher quality meat. WPH-lettuce can substitute nitrate-fertilized lettuce in feeding rabbits for better performance and health aspects.


Assuntos
Peso Corporal/efeitos dos fármacos , Alface/efeitos dos fármacos , Carne/normas , Nitratos/toxicidade , Hidrolisados de Proteína/administração & dosagem , Proteínas do Soro do Leite/administração & dosagem , Animais , Peso Corporal/fisiologia , Suplementos Nutricionais , Alface/crescimento & desenvolvimento , Carne/análise , Coelhos
4.
Genes (Basel) ; 12(6)2021 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-34205694

RESUMO

Lettuce plants tend to undergo floral initiation by elongation of flower stalks (bolting) under high-temperature and long-day conditions, which is a serious problem for summer lettuce production. Our objective was to generate a high-density genetic map using SNPs obtained from genotyping-by-sequencing (GBS) analysis of F5 recombinant inbred lines (RILs) and to map QTLs involved in stem growth and flowering time in lettuce. A set of 127 intra-specific RIL mapping populations derived from a cross between two varieties, green and red leaf lettuce, were used to identify QTLs related to the number of days from sowing to bolting (DTB), to flowering of the first flower (DTF), to seed-setting of the first flower (DTS), and the total number of leaves (LN), plant height (PH), and total number of branches of main inflorescence (BN) for two consecutive years. Of the 15 QTLs detected, one that controls DTB, DTF, DTS, LN, and PH detected on LG 7, and another QTL that controls DTF, DTS, and PH detected on LG 1. Analysis of the genomic sequence corresponding to the QTL detected on LG 7 led to the identification of 22 putative candidate genes. A consistent QTL related to bolting and flowering time, and corresponding candidate genes has been reported. This study will be valuable in revealing the genetic basis of stem growth and flowering time in lettuce.


Assuntos
Alface/genética , Locos de Características Quantitativas , Flores/genética , Flores/crescimento & desenvolvimento , Estudo de Associação Genômica Ampla , Técnicas de Genotipagem , Alface/crescimento & desenvolvimento , Caules de Planta/genética , Caules de Planta/crescimento & desenvolvimento
5.
Theor Appl Genet ; 134(10): 3319-3337, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34196730

RESUMO

KEY MESSAGE: Photoperiod and temperature conditions elicit different genetic regulation over lettuce bolting and flowering. This study identifies environment-specific QTLs and putative genes and provides information for genetic marker assay. Bolting, defined as stem elongation, marks the plant life cycle transition from vegetative to reproductive stage. Lettuce is grown for its leaf rosettes, and premature bolting may reduce crop quality resulting in economic losses. The transition to reproductive stage is a complex process that involves many genetic and environmental factors. In this study, the effects of photoperiod and ambient temperature on bolting and flowering regulation were studied by utilizing a lettuce mapping population to identify quantitative trait loci (QTL) and by gene expression analyses of genotypes with contrasting phenotypes. A recombinant inbred line (RIL) population, derived from a cross between PI 251246 (early bolting) and cv. Salinas (late bolting), was grown in four combinations of short (8 h) and long (16 h) days and low (20 °C) and high (35 °C) temperature. QTL models revealed both genetic (G) and environmental (E) effects, and GxE interactions. A major QTL for bolting and flowering time was found on chromosome 7 (qFLT7.2), and two candidate genes were identified by fine mapping, homology, and gene expression studies. In short days and high temperature conditions, qFLT7.2 had no effect on plant development, while several small-effect loci on chromosomes 2, 3, 6, 8, and 9 were associated with bolting and flowering. Of these, the QTL on chromosome 2, qBFr2.1, co-located with the Flowering Locus T (LsFT) gene. Polymorphisms between parent genotypes in the promotor region may explain identified gene expression differences and were used to design a genetic marker which may be used to identify the late bolting trait.


Assuntos
Mapeamento Cromossômico/métodos , Cromossomos de Plantas/genética , Flores/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Alface/crescimento & desenvolvimento , Proteínas de Plantas/metabolismo , Locos de Características Quantitativas , Flores/genética , Alface/genética , Fenótipo , Fotoperíodo , Proteínas de Plantas/genética
6.
Methods Mol Biol ; 2317: 267-281, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34028775

RESUMO

The interest in producing pharmaceutical proteins in a nontoxic plant host has led to the development of an approach to express such proteins in transplastomic lettuce (Lactuca sativa). A number of therapeutic proteins and vaccine antigen candidates have been stably integrated into the lettuce plastid genome using biolistic DNA delivery. High levels of accumulation and retention of biological activity suggest that lettuce may provide and ideal platform for the production of biopharmaceuticals.


Assuntos
Biolística/métodos , Engenharia Genética/métodos , Alface/genética , Folhas de Planta/genética , Plantas Geneticamente Modificadas/genética , Plastídeos/genética , Transformação Genética , Produtos Biológicos/administração & dosagem , Alface/crescimento & desenvolvimento , Folhas de Planta/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/crescimento & desenvolvimento
7.
Molecules ; 26(7)2021 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-33808049

RESUMO

Cyclic imides belong to a well-known class of organic compounds with various biological activities, promoting a great interest in compounds with this functional group. Due to the structural complexity of some molecules and their spectra, it is necessary to use several spectrometric methods associated with auxiliary tools, such as the theoretical calculation for the structural elucidation of complex structures. In this work, the synthesis of epoxy derivatives of 5-methylhexahydroisoindole-1,3-diones was carried out in five steps. Diels-Alder reaction of isoprene and maleic anhydride followed by reaction with m-anisidine afforded the amide (2). Esterification of amide (2) with methanol in the presence of sulfuric acid provided the ester (3) that cyclized in situ to give imides 4 and 4-ent. Epoxidation of 4 and 4-ent with meta-chloroperbenzoic acid (MCPBA) afforded 5a and 5b. The diastereomers were separated by silica gel flash column chromatography, and their structures were determined by analyses of the spectrometric methods. Their structures were confirmed by matching the calculated 1H and 13C NMR chemical shifts of (5a and 5b) with the experimental data of the diastereomers using MAE, CP3, and DP4 statistical analyses. Biological assays were carried out to evaluate the potential herbicide activity of the imides. Compounds 5a and 5b inhibited root growth of the weed Bidens pilosa by more than 70% at all the concentrations evaluated.


Assuntos
Compostos de Epóxi , Herbicidas , Imidas , Sementes/crescimento & desenvolvimento , Bidens/crescimento & desenvolvimento , Cucumis sativus/crescimento & desenvolvimento , Compostos de Epóxi/síntese química , Compostos de Epóxi/química , Herbicidas/síntese química , Herbicidas/química , Imidas/síntese química , Imidas/química , Alface/crescimento & desenvolvimento , Estrutura Molecular , Sorghum/crescimento & desenvolvimento
8.
J Sci Food Agric ; 101(14): 5888-5897, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33797092

RESUMO

BACKGROUND: Urban agriculture contributes to meeting the growing food production demand in cities. In the context of low water availability, it is important to consider alternatives that are able to maintain production. Through a circular economy vision, this study aimed to assess the use of substrates made from local materials as an alternative for urban agriculture in periods of low water availability, due to water supply cuts. The substrates used were coir commercial organic substrate, vegetable compost from urban organic waste and perlite commercial standard substrate; a mixture of the urban compost and perlite (1:1) was used for three consecutive crop cycles of lettuce (Lactuca sativa L. var. crispa). The crop cycles were performed in the spring and summer periods of 2018 to observe the performance during warmer periods of the year in an integrated rooftop greenhouse near Barcelona. Each substrate was assessed under conventional irrigation (0-5 kPa) and temporary water restricted conditions (irrigation stopped until the water tension reached -20 kPa perlite). RESULTS: In terms of yield, our results show that the compost and mixture were similar to those obtained from perlite (11.5% and 3.7% more production under restricted water conditions). Organic substrates increased the crop's resilience to water restriction, in contrast to the perlite. In particular, water loss took longer in coir (one- and two-crop cycle); however, when dryness began, it occurred quickly. CONCLUSION: The vegetable compost and the substrate mixture presented tolerance to temporary water restriction when water restriction reached -20 kPa. © 2021 Society of Chemical Industry.


Assuntos
Produção Agrícola/métodos , Alface/crescimento & desenvolvimento , Cidades , Produção Agrícola/instrumentação , Secas , Alface/metabolismo , Região do Mediterrâneo , Solo/química , Água/análise , Água/metabolismo
9.
J Sci Food Agric ; 101(13): 5688-5696, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33786828

RESUMO

BACKGROUND: Salinity and drought stresses have become widespread in many regions of the world. Although there are several studies, their findings about the response of lettuce to water and salinity stresses are contradictory. This paper therefore aims to evaluate the effects of water deficit and irrigation water salinity on growth, yield, and water consumption of iceberg lettuce. For these purposes, two experiments were carried out under Mediterranean conditions. RESULTS: The water yield response factors (Ky ) determined for the lettuce plant grown under stress conditions caused by water (Ky  = 1.69) and irrigation water salinity (Ky  = 2.62) were quite different from each other. The classical salinity tolerance model did not reflect the results accurately because the fresh yield and plant water consumption of lettuce increased sharply with increasing soil salinity up to 2.17 dS m-1 and then decreased slightly after this value. Thus, a new model was created to reflect both the increase and decrease in fresh yield. The actual salt tolerance model for iceberg lettuce plant showed that the optimum salinity is 1.84 dS m-1 with relative yield decreases of 8.26 and 22.7% per unit salinity increase above and below the optimum salinity level, respectively. CONCLUSION: Lettuce fresh yield at soil salinity below the optimum salinity experienced greater reduction than at soil salinity above the optimum value. The results reveal that the use of low-salinity irrigation water should be preferred to increase fresh yield in iceberg lettuce cultivation. © 2021 Society of Chemical Industry.


Assuntos
Alface/crescimento & desenvolvimento , Alface/metabolismo , Cloreto de Sódio/análise , Água/química , Irrigação Agrícola , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Salinidade , Tolerância ao Sal , Cloreto de Sódio/metabolismo , Solo/química , Água/metabolismo
10.
Braz J Microbiol ; 52(2): 727-738, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33694059

RESUMO

Azo dyes are widely used in the textile industry due to their resistance to light, moisture, and oxidants. They are also an important class of environmental contaminant because of the amount of dye that reaches natural water resources and because they can be toxic, mutagenic, and carcinogenic. Different technologies are used for the decolorization of wastewater containing dyes; among them, the biological processes are the most promising environmentally. The aim of this study was to evaluate the potential of Phanerochaete chrysosporium strain ME-446 to safely decolorize three azo dyes: Direct Yellow 27 (DY27), Reactive Black 5 (RB5), and Reactive Red 120 (RR120). Decolorization efficiency was determined by ultraviolet-visible spectrophotometry and the phytotoxicity of the solutions before and after the fungal treatment was analyzed using Lactuca sativa seeds. P. chrysosporium ME-446 was highly efficient in decolorizing DY27, RB5, and RR120 at 50 mg L-1, decreasing their colors by 82%, 89%, and 94% within 10 days. Removal of dyes was achieved through adsorption on the fungal mycelium as well as biodegradation, inferred by the changes in the dyes' spectral peaks. The intensive decolorization of DY27 and RB5 corresponded to a decrease in phytotoxicity. However, phytotoxicity increased during the removal of color for the dye RR120. The ecotoxicity tests showed that the absence of color does not necessarily translate to an absence of toxicity.


Assuntos
Compostos Azo/metabolismo , Phanerochaete/metabolismo , Poluentes Químicos da Água/metabolismo , Compostos Azo/toxicidade , Biodegradação Ambiental , Fermentação , Alface/efeitos dos fármacos , Alface/crescimento & desenvolvimento , Micélio/metabolismo , Naftalenos/metabolismo , Naftalenos/toxicidade , Naftalenossulfonatos/metabolismo , Naftalenossulfonatos/toxicidade , Águas Residuárias/química , Águas Residuárias/microbiologia , Poluentes Químicos da Água/toxicidade
11.
J Environ Sci Health B ; 56(5): 439-446, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33760685

RESUMO

The aims of this research were 1) to find out the possible microbiological contamination and residues of pesticides (chlorpyrifos and cypermethrin) in lettuce grown in Bahía Blanca's horticultural belt, and bacteriological quality of waters used for irrigation and post-harvest washing, 2) to investigate and compare the internalization capacity of a strain of Escherichia coli isolated from irrigation water with another hospital uropathogenic strain. Some strains of bacteria can internalize into the plant tissue. This capability presents food safety threats as they cannot be removed with standard sanitation practices. To determine bacteriological quality of lettuce, E. coli, Salmonella spp and E. coli O157: H7/NM (n = 10) were investigated. Bacteriological quality of water was determined by quantification of fecal coliforms/100 mL (n = 20). Pesticides were determined by using an improved and validated QuEChERS method combined with GC-MSD. Irrigation water in 19/20 samples did not present health risk. Bacteriological quality of lettuce met demands in 9/10 samples. Pesticides were detected in half of the samples, values exceeding the FAO recommendations. An effort is strongly recommended to implement both, best phytosanitary practices and monitoring programmes. Uropathogenic strain was able to internalize into plant tissue, while the nonpathogenic one was not.


Assuntos
Contaminação de Alimentos/análise , Alface/química , Alface/microbiologia , Resíduos de Praguicidas/análise , Argentina , Bactérias/classificação , Bactérias/isolamento & purificação , Brasil , Clorpirifos/análise , Contagem de Colônia Microbiana , Microbiologia de Alimentos , Horticultura , Alface/crescimento & desenvolvimento , Piretrinas/análise , Microbiologia da Água
12.
PLoS One ; 16(2): e0247534, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33621265

RESUMO

The demand for food will outpace productivity of conventional agriculture due to projected growth of the human population, concomitant with shrinkage of arable land, increasing scarcity of freshwater, and a rapidly changing climate. While aquaponics has potential to sustainably supplement food production with minimal environmental impact, there is a need to better characterize the complex interplay between the various components (fish, plant, microbiome) of these systems to optimize scale up and productivity. Here, we investigated how the commonly-implemented practice of continued microbial community transfer from pre-existing systems might promote or impede productivity of aquaponics. Specifically, we monitored plant growth phenotypes, water chemistry, and microbiome composition of rhizospheres, biofilters, and fish feces over 61-days of lettuce (Lactuca sativa var. crispa) growth in nitrogen-limited aquaponic systems inoculated with bacteria that were either commercially sourced or originating from a pre-existing aquaponic system. Lettuce above- and below-ground growth were significantly reduced across replicates treated with a pre-existing aquaponic system inoculum when compared to replicates treated with a commercial inoculum. Reduced productivity was associated with enrichment in specific bacterial genera in plant roots, including Pseudomonas, following inoculum transfer from pre-existing systems. Increased productivity was associated with enrichment of nitrogen-fixing Rahnella in roots of plants treated with the commercial inoculum. Thus, we show that inoculation from a pre-existing system, rather than from a commercial inoculum, is associated with lower yields. Further work will be necessary to test the putative mechanisms involved.


Assuntos
Hidroponia/métodos , Alface/crescimento & desenvolvimento , Microbiota , Nitrogênio/análise , Alface/microbiologia , Desenvolvimento Vegetal/fisiologia
13.
Chem Biodivers ; 18(3): e2000928, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33555653

RESUMO

Nine new ß-resorcylic acid derivatives, (15S)-de-O-methyllasiodiplodin (1), (13S,15S)-13-hydroxy-de-O-methyllasiodiplodin (2), (14S,15S)-14-hydroxy-de-O-methyllasiodiplodin (3), (13R,14S,15S)-13,14-dihydroxy-de-O-methyllasiodiplodin (4), ethyl (S)-2,4-dihydroxy-6-(8-hydroxynonyl)benzoate (5), ethyl 2,4-dihydroxy-6-(8-hydroxyheptyl)benzoate (6), ethyl 2,4-dihydroxy-6-(4-methoxycarbonylbutyl)benzoate (7), 3-(2-ethoxycarbonyl-3,5-dihydroxyphenyl)propionic acid (8), and isobutyl (S)-2,4-dihydroxy-6-(8-hydroxynonyl)benzoate (9), together with a known ethyl 2,4-dihydroxy-6-(8-oxononyl)benzoate (10) were obtained from Lasiodiplodia theobromae GC-22. The structures of these compounds were elucidated by extensive spectroscopic analyses. Compounds 1, 3, and 6 showed growth inhibitory effects against Digitaria ciliaris. Conversely, treatment with compounds 5, 6, 7, 9, and 10 stimulated elongation activity toward the root of Lactuca sativa. These data expand the repertoire of new ß-resorcylic acid derivatives that may function as lead compounds in the synthesis of new agrochemical agents.


Assuntos
Agroquímicos/farmacologia , Ascomicetos/química , Digitaria/efeitos dos fármacos , Hidroxibenzoatos/farmacologia , Alface/efeitos dos fármacos , Agroquímicos/química , Agroquímicos/isolamento & purificação , Digitaria/crescimento & desenvolvimento , Hidroxibenzoatos/química , Hidroxibenzoatos/isolamento & purificação , Alface/crescimento & desenvolvimento , Estrutura Molecular , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Estereoisomerismo
14.
Commun Biol ; 4(1): 124, 2021 01 27.
Artigo em Inglês | MEDLINE | ID: mdl-33504914

RESUMO

Bioregenerative life-support systems (BLSS) involving plants will be required to realize self-sustaining human settlements beyond Earth. To improve plant productivity in BLSS, the quality of the solar spectrum can be modified by lightweight, luminescent films. CuInS2/ZnS quantum dot (QD) films were used to down-convert ultraviolet/blue photons to red emissions centered at 600 and 660 nm, resulting in increased biomass accumulation in red romaine lettuce. All plant growth parameters, except for spectral quality, were uniform across three production environments. Lettuce grown under the 600 and 660 nm-emitting QD films respectively increased edible dry mass (13 and 9%), edible fresh mass (11% each), and total leaf area (8 and 13%) compared with under a control film containing no QDs. Spectral modifications by the luminescent QD films improved photosynthetic efficiency in lettuce and could enhance productivity in greenhouses on Earth, or in space where, further conversion is expected from greater availability of ultraviolet photons.


Assuntos
Produtos Agrícolas , Ambiente Controlado , Alface , Pontos Quânticos , Espectro de Ação/métodos , Espectro de Ação/normas , Biofortificação/métodos , Calibragem , Cobre/química , Produtos Agrícolas/química , Produtos Agrícolas/efeitos da radiação , Radiação Eletromagnética , Humanos , Alface/crescimento & desenvolvimento , Alface/metabolismo , Alface/efeitos da radiação , Luz , Fotossíntese/efeitos da radiação , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/efeitos da radiação , Melhoria de Qualidade , Pontos Quânticos/química , Atividade Solar , Sulfetos/química , Compostos de Zinco/química
15.
J Sci Food Agric ; 101(11): 4632-4642, 2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-33474734

RESUMO

BACKGROUND: Red lettuce is consumed worldwide because it is a great source of natural antioxidants. To design a fertilizer formula to boost its nutritional value, this research simultaneously studied the effects of significant cations among the macronutrients for plant growth (K, Mg and Ca) and the effects of the electrical conductivity (EC) of the nutrient solution on phenolic compound production and mass productivity of hydroponically grown red lettuce. RESULTS: Red lettuce grown under the control treatment provided the highest mass productivity (under low-stress conditions). The highest antioxidant content, measured as milligrams of phenolic compounds per gram dry weight (at a high-stress condition) via both Folin-Ciocalteu and HPLC analyses, was observed in growth media containing 100 ppmK : 20 ppm Mg : 70 ppm Ca (with EC equal to 1241 µS cm-1 ). It was found that EC within the range of this examination had no significant effect on the mass productivity or on phenolic compound productivity. The phenolic compound productivity, defined as the amount of phenolic compounds produced per unit of planting area per unit of time, was optimized with the optimum formula for maximum phenolic compound productivity of 90 ppm K : 29 ppm Mg : 77 ppm Ca, or a corresponding EC of 1307 µS cm-1 . CONCLUSIONS: The study demonstrates that health-promoting nutrient production in red lettuce could be stimulated in a practical manner by adjusting the cation concentrations in fertilizer solution. © 2021 Society of Chemical Industry.


Assuntos
Antioxidantes/metabolismo , Fertilizantes/análise , Alface/crescimento & desenvolvimento , Folhas de Planta/química , Antioxidantes/química , Cátions/análise , Cátions/metabolismo , Hidroponia , Alface/química , Alface/metabolismo , Nutrientes/análise , Nutrientes/metabolismo , Valor Nutritivo , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo
16.
Food Microbiol ; 95: 103691, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33397620

RESUMO

Escherichia coli O157:H7 risk associated with the consumption of fresh cut-cos lettuce during Australian industrial practices was assessed. A probabilistic risk assessment model was developed and implemented in the @Risk software by using the Monte Carlo simulation technique with 1,000,000 iterations. Australian preharvest practices yielded predicted annual mean E. coli O157:H7 levels from 0.2 to -3.4 log CFU/g and prevalence values ranged from 2 to 6.4%. While exclusion of solar radiation from the baseline model yielded a significant increase in concentration of E. coli O157:H7 (-5.2 -log fold), drip irrigation usage, exclusion of manure amended soil and rainfall reduced E. coli O157:H7 levels by 7.4, 6.5, and 4.3-log fold, respectively. The microbial quality of irrigation water and irrigation type both had a significant effect on E. coli O157:H7 concentrations at harvest (p < 0.05). The probability of illness due to consumption of E. coli O157:H7 contaminated fresh cut-cos lettuce when water washing interventions were introduced into the processing module, was reduced by 1.4-2.7-log fold (p < 0.05). This study provides a robust basis for assessment of risk associated with E. coli O157:H7 contamination on fresh cut-cos lettuce for industrial practices and will assist the leafy green industry and food safety authorities in Australia to identify potential risk management strategies.


Assuntos
Escherichia coli O157/crescimento & desenvolvimento , Contaminação de Alimentos/análise , Alface/microbiologia , Irrigação Agrícola , Austrália , Contagem de Colônia Microbiana , Escherichia coli O157/genética , Escherichia coli O157/isolamento & purificação , Água Doce/microbiologia , Alface/crescimento & desenvolvimento , Esterco/microbiologia , Folhas de Planta/microbiologia
17.
J Sci Food Agric ; 101(4): 1403-1410, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-32833277

RESUMO

BACKGROUND: Most hydroponic lettuce growers harvest and package their marketable-size lettuces with an intact root ball. With a high microbial load on the peat moss substrate, there is a risk of microbial transfer onto the edible portion during packaging and throughout the product's shelf life. Since the produce is believed to have no contact with the substrate, no sanitizer wash is performed before packaging and storage. RESULTS: Aerobic plate count (APC) results suggested that reduction in count was influenced by both sanitizer application and storage time. Peroxyacetic acid significantly reduced APC count on leaves, roots, and substrate, with a 1.8 log CFU g-1 initial reduction on the leaf. Fungi and APC levels increased with storage time, with the greatest APC increase in the roots. Leaves had the lowest coliform bacteria (CB), with chlorine slightly reducing CB count. Unlike APC, CB levels decreased during storage on the substrate and root samples. No Listeria positive was confirmed by agglutination test. Further evaluation of different commercial substrates reveals that Com4, a drier-compacted plug, had the least ability to support growth/survival of all microbial populations enumerated relative to the spongy, wet black plugs. CONCLUSION: The ability of peat moss substrates to host microorganisms is influenced by the physical properties of the product. Sanitizer wash efficacy is dependent on the initial microbial load and the length of storage. Chlorine and peroxyacetic acid are effective in reducing microbial populations on the leaves of hydroponically grown lettuce without affecting visual quality during shelf life. © 2020 Society of Chemical Industry.


Assuntos
Bactérias/efeitos dos fármacos , Cloro/farmacologia , Desinfetantes/farmacologia , Fungos/efeitos dos fármacos , Alface/crescimento & desenvolvimento , Ácido Peracético/farmacologia , Folhas de Planta/microbiologia , Bactérias/classificação , Bactérias/crescimento & desenvolvimento , Bactérias/isolamento & purificação , Desinfecção , Contaminação de Alimentos/análise , Contaminação de Alimentos/prevenção & controle , Manipulação de Alimentos , Fungos/classificação , Fungos/crescimento & desenvolvimento , Hidroponia , Alface/química , Alface/microbiologia , Folhas de Planta/química , Folhas de Planta/crescimento & desenvolvimento
18.
Environ Geochem Health ; 43(1): 423-439, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32990874

RESUMO

Plant leaves can intercept and directly absorb nanoparticles (NPs) that deposit on their surface, which can lead severe phytotoxicity. However, there is a large blind spot when it comes to the fate and phytotoxicity of NPs after leaf exposure, even though foliar uptake is likely to occur. In this study, lettuce leaves (Lactuca sativa L. var. ramosa Hort.) were exposed to different concentrations of copper-oxide NPs (CuO-NPs, 0, 100, and 1000 mg L-1) for 5, 10, and 15 days. Foliar uptake, subcellular distribution, chemical forms, and impact of CuO-NPs on nutrient status, antioxidant systems, and lettuce growth were examined. Substantially elevated Cu levels were observed in lettuce leaves (up to 6350 mg kg-1), which was one magnitude greater than that in the roots (up to 525 mg kg-1). Cu translocation factors from leaves to roots ranged from 1.80 to 15.6%. The application of CuO-NPs severely inhibited lettuce growth and altered the nutrient status in plants (especially Mn, K, and Ca). Moreover, CuO-NPs increased H2O2 generation, malonaldehyde level (on the 5th and 10th day of exposure), and catalase activity (on the 15th day of exposure) in lettuce leaves. The Cu concentrations in subcellular fractions were ranked: cell wall ≈ organelles > soluble fraction in lettuce leaves, and organelles > cell wall > soluble fraction in lettuce roots. Undissolved Cu forms were predominant in lettuce, which may have helped to reduce the Cu's mobility and phytotoxicity in the plant. The findings of this study will be of great interest in areas with high levels of metal-NPs in the atmosphere.


Assuntos
Cobre/metabolismo , Cobre/toxicidade , Alface/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Antioxidantes/metabolismo , Biotransformação , Peróxido de Hidrogênio/metabolismo , Alface/crescimento & desenvolvimento , Alface/metabolismo , Nutrientes/análise , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Frações Subcelulares/metabolismo
19.
Nat Prod Res ; 35(9): 1525-1531, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-31450988

RESUMO

The endophytic fungus, Clonostachys rosea B5-2 was isolated from mangrove plants and subjected to the one strain many compounds (OSMAC) methodology. By this approach, it was found that modification of the culture media enhanced the production of secondary metabolites by C. rosea B5-2. The apple juice supplemented solid rice media led to significant changes in the secondary metabolism of the fungus, C. rosea B5-2, and induced the production of four new compounds, (-)-dihydrovertinolide (2), and clonostach acids A (3), B (4), and C (5) together with the known compound, (-)-vertinolide (1). The new compound (-)-dihydrovertinolide (2) exhibited phytotoxicity against lettuce seedlings at a concentration of 50 mg L-1.


Assuntos
Endófitos/metabolismo , Hypocreales/metabolismo , Metaboloma , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Meios de Cultura , Alface/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Oryza , Espectroscopia de Prótons por Ressonância Magnética , Metabolismo Secundário , Plântula
20.
J Agric Food Chem ; 69(2): 805-814, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-33249847

RESUMO

Here, coal-related humic substances (HSs) were examined to confirm whether sterilization treatments induce their inferior ability to stimulate lettuce in hydroponic cultivations. Interestingly, a drastic reduction in both lettuce biomass and microbial colony-forming units of the crop culture solutions was observed when the autoclaved HSs were treated. Some microbial genera (i.e., Bacillus and Aspergillus) identifiable in the bare HS-treated hydroponic systems were able to be isolated by direct inoculation of bare HS powders on conventional microbial nutrients, supporting that flourishing microbes in the hydroponic cultivations derive from bare HSs-treated. Moreover, coincubation of some isolated bacterial and fungal strains (i.e., Bacillus and Aspergillus genera) from HSs with lettuce resulted in a significant increase in plant biomass and enhanced resistance to NaCl-related abiotic stresses. Microbial volatile organic compounds renowned for plant stimulation were detected by using solid-phase microextraction coupled with gas chromatography-mass spectrometry. It was finally confirmed that the isolates are capable of utilizing carbon substrates such as pectin and tween 20 or 40, which are relevant to those of microbes isolated from peat and leonardite (i.e., HS extraction sources). Overall, our results suggest that microbiological factors could be considered when commercial coal-related HSs are applied in hydroponic crop cultivations.


Assuntos
Bactérias/isolamento & purificação , Carvão Mineral/microbiologia , Fungos/isolamento & purificação , Substâncias Húmicas/microbiologia , Alface/crescimento & desenvolvimento , Microbiota , Bactérias/classificação , Bactérias/genética , Fungos/classificação , Fungos/genética , Substâncias Húmicas/análise , Hidroponia , Alface/microbiologia , Solo/química
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