Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 9.288
Filtrar
1.
Braz. j. biol ; 84: e257739, 2024. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1355883

RESUMO

Abstract Under salt stress conditions, plant growth is reduced due to osmotic, nutritional and oxidative imbalance. However, salicylic acid acts in the mitigation of this abiotic stress by promoting an increase in growth, photosynthesis, nitrogen metabolism, synthesis of osmoregulators and antioxidant enzymes. In this context, the objective was to evaluate the effect of salicylic acid doses on the growth and physiological changes of eggplant seedlings under salt stress. The experiment was conducted in a greenhouse, where the treatments were distributed in randomized blocks using a central composite matrix Box with five levels of electrical conductivity of irrigation water (CEw) (0.50; 1.08; 2.50; 3.92 and 4.50 dS m-1), associated with five doses of salicylic acid (SA) (0.00; 0.22; 0.75; 1.28 and 1.50 mM), with four repetitions and each plot composed of three plants. At 40 days after sowing, plant height, stem diameter, number of leaves, leaf area, electrolyte leakage, relative water content, and total dry mass were determined. ECw and SA application influenced the growth and physiological changes of eggplant seedlings. Increasing the ECw reduced growth in the absence of SA. Membrane damage with the use of SA remained stable up to 3.9 dS m-1 of ECw. The relative water content independent of the CEw increased with 1.0 mM of SA. The use of SA at the concentration of 1.0 mM mitigated the deleterious effect of salinity on seedling growth up to 2.50 dS m-1 of ECw.


Resumo Em condições de estresse salino, o crescimento das plantas é reduzido, em virtude, do desequilíbrio osmótico, nutricional e oxidativo. Contudo, o ácido salicílico atua na mitigação desse estresse abiótico por promover incremento no crescimento, fotossíntese, metabolismo do nitrogênio, síntese de osmorreguladores e enzimas antioxidantes. Nesse contexto, objetivou-se avaliar o efeito de doses de ácido salicílico sobre o crescimento e alterações fisiológicas de mudas de berinjela sob estresse salino. O experimento foi conduzido em casa de vegetação, onde os tratamentos foram distribuídos em blocos ao acaso utilizando uma matriz composta central Box com cinco níveis de condutividade elétrica da água de irrigação (CEa) (0,50; 1,08; 2,50; 3,92 e 4,50 dS m-1), associada a cinco doses de ácido salicílico (AS) (0,00; 0,22; 0,75; 1,28 e 1,50 mM), com quatro repetições e cada parcela composta por três plantas. Aos 40 dias após a semeadura, foram determinados a altura da planta, diâmetro do caule, número de folhas, área foliar, vazamento de eletrólito, teor relativo de água e massa seca total. A CEa e a aplicação de AS influenciaram no crescimento e nas alterações fisiológicas das mudas de berinjela. O aumento da CEa reduziu o crescimento na ausência de AS. O dano de membrana com o uso de AS manteve-se estável até 3,9 dS m-1 de CEa. O conteúdo relativo de água independentemente da CEa aumentou com 1 mM de SA. O uso de AS na concentração de 1 mM mitigou o efeito deletério da salinidade no crescimento das mudas até 2,50 dS m-1 de CEa.


Assuntos
Ácido Salicílico/farmacologia , Solanum melongena/metabolismo , Fotossíntese , Estresse Fisiológico , Folhas de Planta/metabolismo , Plântula , Salinidade , Tolerância ao Sal , Antioxidantes/metabolismo
2.
Braz. j. biol ; 84: e254161, 2024. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1364527

RESUMO

Salinity is one of the most critical environmental parameters regarding fish physiology, modifying food intake and growth performance in many fish species. The present study has investigated the effects of different salinity levels on growth performance, feeding and survival of Asian seabass Lates calcarifer juveniles. Asian seabass juveniles were reared at 0 (T1), 5 (T2), 22 (T3), 36 (T4), and 42 (T5) ppt salinity. Approximately eight hundred thirty fish individuals with an average weight of 1.24±0.52 g were randomly distributed (166 fish/Tank) in 5 concrete tanks (each tank 30×6×4 ft, volume 19,122 L) for forty days. Juveniles were initially fed 42% crude protein-containing diets at a rate of 6% of their body weight per day. The results showed that salinity level had a significant effect on the weight gain (WG), average daily weight gain (ADWG), specific growth rate (SGR), feed conversion ratio (FCR), survival rate (SR), total biomass and health indices (p<0.05). The highest WG (39.11±1.49 g), ADWG (1.00±0.12 g), SGR (8.74±0.03% d-1) and lowest FCR (0.96±0.20) were observed with T3 treatment, which was significantly higher compared to other treatment groups (p<0.05). Among the health indices, the highest hepatosomatic index and viscerosomatic index were found with T3 treatment, significantly higher than the other groups (p<0.05). No significant differences were found among the treatments in terms of survival rate (p>0.05), but the maximum survival rate (98.89±0.0%) was observed in the T3 and T2 treatments. The maximum level of crude proteins (19.99±1.4%) was found in the whole-body biochemical composition of Asian seabass juveniles in the T3 treatment group. The second-order polynomial regression showed that 20 ppt salinity is optimum for the best growth of Asian seabass. Thus, the present study recommends 20 to 36 ppt salinity for the commercial farming of Asian seabass under a closed aquaculture system.


A salinidade é um dos parâmetros ambientais mais críticos em relação à fisiologia dos peixes, modificando a ingestão de alimentos e o desempenho de crescimento em muitas espécies. O presente estudo investigou os efeitos de diferentes níveis de salinidade no desempenho de crescimento, alimentação e sobrevivência de jovens espécies de robalos asiáticos Lates calcarifer, as quais foram criadas sob salinidade 0 (T1), 5 (T2), 22 (T3), 36 (T4) e 42 (T5) ppt. Aproximadamente 830 indivíduos de peixes com peso médio de 1,24 ± 0,52 g foram distribuídos aleatoriamente (166 peixes / tanque) em cinco tanques de concreto (cada tanque tinha 30 × 6 × 4 pés (9,1 x 1,8 x 1,2 metros), com volume de 19,12 litros) por 40 dias. Os peixes foram inicialmente alimentados com uma dieta contendo 42% de proteína bruta a uma taxa de 6% do seu peso corporal por dia. Os resultados mostraram que o nível de salinidade teve um efeito significativo no ganho de peso (GP), ganho de peso médio diário (GPMD), taxa de crescimento específico (TCE), taxa de conversão alimentar (TCA), taxa de sobrevivência (TS), biomassa total e índices de saúde (p < 0,05). O maior GP (39,11 ± 1,49 g), GPMD (1,00 ± 0,12 g), TCE (8,74 ± 0,03% d-1) e o menor TCA (0,96 ± 0,20) foram observados com o tratamento T3, que foi significativamente superior em comparação com os outros tratamentos (p < 0,05). Entre os índices de saúde, os maiores índices hepatossomáticos e viscerossomáticos foram encontrados no tratamento T3, significativamente superior do que os demais grupos (p < 0,05). Não foram encontradas diferenças significativas entre os tratamentos quanto à TS (p > 0,05), mas a TS máxima (98,89 ± 0,0%) foi observada nos tratamentos T3 e T2. O nível máximo de proteína bruta (19,99 ± 1,4%) foi encontrado na composição bioquímica dos corpos dos jovens robalos asiáticos no grupo T3. A regressão polinomial de segunda ordem mostrou que a salinidade de 20 ppt é ótima para o melhor crescimento do robalo asiático. Assim, o presente estudo recomenda salinidade de 20 a 36 ppt para o cultivo comercial de robalo asiático em sistema de aquicultura fechado.


Assuntos
Animais , Aquicultura , Salinidade , Peixes/crescimento & desenvolvimento , Sobrevivência
3.
Sci Rep ; 12(1): 15545, 2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-36109552

RESUMO

Humic ligands from boreal rivers have been identified as important sources of iron-binding ligands to the coastal marine environment but remain poorly characterized. A novel method using Fourier transformed infrared spectroscopy (FTIR) was used to identify and quantify iron-binding ligands present in a boreal river in Newfoundland, Canada. 20 to 35% of the total iron load was carried through an artificial salinity gradient, and remained in solution at 35 salinity. Using FTIR combined with linear regression and 2D correlation analysis, we identified two pools of organic ligands, with different behaviour with regards to iron across the salinity gradient. The weaker ligand pool consisted of alkenes, ethers, and esters, and was found to release iron to flocculation at low salinities, and not contribute to iron transport into the marine environment. The stronger ligand group contained carboxylic acids and aliphatic functional groups. This group appears to contain two subgroups, one which was able to retain iron in the dissolved phase at 35 salinity, and another that flocculated out with iron across the salinity gradient. The strong ligands that retain iron in solution through the salinity gradient provide a much-needed source of the micronutrient to the coastal and marine environment, while the other subgroup sequesters iron and carbon in estuarine sediments. The balance between these two subgroups appears to be controlled by the hydrographic and weather conditions at the time of sampling, suggesting a dynamic ligand-iron relationship throughout the year, impacting the biogeochemical cycles of both iron and carbon in contrasting ways.


Assuntos
Salinidade , Água do Mar , Alcenos , Carbono/análise , Ácidos Carboxílicos , Éteres , Ferro/química , Ligantes , Micronutrientes/análise , Água do Mar/química
4.
Science ; 377(6612): 1248-1249, 2022 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-36108012

RESUMO

Drought spurs efforts to restore shrinking lake's water supplies.


Assuntos
Lagos , Salinidade , Secas
5.
ScientificWorldJournal ; 2022: 5245928, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36105736

RESUMO

In order to understand the incipient movement of muddy clay under different salinity conditions, three series of flume tests were performed on incipient movement of muddy clay, including tests on incipient movement of salt-free clay mud under salt water conditions (salt water-salt-free clay mud), incipient movement of salt clay mud under salt water conditions (salt water-salt clay mud), and incipient movement of salt clay mud under freshwater conditions (freshwater-salt clay mud), using a circulating flume, in which the salinity of the water body or cohesive sediment varies from 0 to 40%. Based on the particle image velocimetry system and digital image gray processing technology, the gray curves of water near the clay mud bed surface with the velocity were plotted to quantitatively differentiate the incipient velocity of the sediment for each test. The experimental results showed that the higher the salinity of the water body or cohesive sediments is, the more difficult it is to start moving. There is a logarithmic relationship between the incipient velocity of cohesive sediments and the salinity of the water or cohesive sediments. The incipient velocity increases sharply at a salinity of 0∼10% and slowly at a salinity of 10∼40%. At the same salinity, the incipient velocity of salt clay mud under freshwater conditions is the largest, followed by that of salt clay mud under salt water conditions, while that of salt-free clay mud under salt water conditions is the smallest. In addition, the flow turbulence characteristics were analyzed under the critical conditions of the onset of muddy clay. Ultimately, an empirical formula to calculate the critical incipient velocity of muddy clay is proposed by introducing the salinity. In this study, salinity is included as a reference variable, which expands the research scope of sediment initiation and provides a reference for the study of estuary dynamics.


Assuntos
Água Doce , Salinidade , Argila , Água
6.
Pak J Biol Sci ; 25(8): 776-780, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36098204

RESUMO

<b>Background and Objective:</b> Water quality in freshwater bodies is involved with multiple aspects such as physical, chemical and biological processes and their interactions. Due to the vulnerability of water resources, quality control of surface water is one of the key issues in environmental conservation programs. The objectives of the present work were to study the water quality in the Anzali Lagoon and to study the classification of water based on the water quality index in different parts of the Anzali Lagoon. <b>Materials and Methods:</b> In this study, we sampled water from January to December, 2015 in the Anzali Lagoon. All physicochemical parameters were sampled and determined according to standard methods. <b>Results:</b> The Water Quality Index results showed the Anzali Lagoon water quality had been "medium" in site 1 and "bad" in sites 2, 3 and 4. The result showed a significant difference between sit 1 and sites 2, 3 and 4 (p<0.05). However, there was no significant difference between sit 2, 3 and 4 (p>0.05). The result showed a clear spatial separation among parts in the Anzali Lagoon. The Eastern part of the Anzali Lagoon showed lower water quality compared to the central and western stations. <b>Conclusion:</b> This study showed that the level of pollution was different on all of the Anzali Lagoons. The water of the Anzali Lagoon has different quality classes according to the aggregation methods employed. Nutrient loadings from the adjacent agricultural lands combined with high mean salinity values affect all organism conditions. The three primary sources of nutrients, including fertilizers used in agriculture, household waste and livestock waste, reduced the water quality of the Anzali Lagoon.


Assuntos
Monitoramento Ambiental , Qualidade da Água , Monitoramento Ambiental/métodos , Análise Multivariada , Salinidade
7.
Water Environ Res ; 94(9): e10789, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36102325

RESUMO

Some wastewaters contain high concentrations of ammonia coexisting with large amounts of salt, which might negatively affect the anaerobic ammonium oxidation (anammox) process. In this study, the performance of the anammox process under different saline conditions was investigated using an upflow anaerobic sludge bed-anammox system. After long-term operating for 275 days, the results indicated that the nitrogen removal efficiency remained high under the 0-40 g NaCl/L, and low salinity (15 g NaCl/L) substantially promoted specific anammox activity. Affected by the saline environment, the appearance, color, and shape of sludge notably changed, and the amount of extracellular polymeric substances gradually increased with increasing salinity, which might be one of the reasons for the strong salt tolerance of the system. Chloroflexi and Planctomycetes were the dominant strains under long-term salinity, and Brocadiaceae_g_ unclassified exhibited halophilic characteristics. The redundancy analysis results showed that the concentration of influent NH4 + -N and salinity were the main environmental factors affecting the microbial community of the system. PRACTITIONER POINTS: Provides data to support the maximum value for salinity wastewater treatment with anammox processes' tolerance of 40 g NaCl/L. EPS changes may be responsible for the response to salinity challenges and provide direction for high salinity wastewater treatment. Brocadiaceae_g_ unclassified exhibited a halophilic quality. And it can be focused on to improve treatment efficiency.


Assuntos
Salinidade , Esgotos , Oxidação Anaeróbia da Amônia , Reatores Biológicos , Cloreto de Sódio
8.
Mar Environ Res ; 180: 105736, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36049432

RESUMO

Triphenyltin (TPT) has attracted considerable attention owing to its vitality, bioaccumulation, and lurking damage. TPT widely exists in complex salinity areas such as estuaries and coastal regions. However, there are few studies on the toxicological behavior of TPT under different salinity. In the study, juvenile Nile tilapia (Oreochromis niloticus) were utilized as model animals to investigate the effects of environmental relevant TPT exposure on the osmoregulation and energy metabolism in gill under different salinity. The results showed that salinity and TPT single or combined exposure affected the morphology of the gill tissue. After TPT exposure, Na+-K+-ATPase (NKA) activity significantly decreased at 0 ppt, while NKA and Ca2+-Mg2+-ATPase (CMA) activities significantly increased at 15 ppt. In addition, significantly higher succinate dehydrogenase (SDH) and lactate dehydrogenase (LDH) activities were found in the control fish compared to the TPT-exposed ones at 15 ppt. Quantitative real-time PCR results showed that TPT exposure affected the expression of osmoregulation and energy metabolism-related genes under different salinity. Overall, TPT exposure interfered with osmoregulation and energy metabolism under different salinity. The study will provide reference data for assessing the toxicity of organotin compounds in complex-salinity areas.


Assuntos
Ciclídeos , Compostos Orgânicos de Estanho , Adenosina Trifosfatases/metabolismo , Animais , Ciclídeos/metabolismo , Brânquias/metabolismo , Compostos Orgânicos de Estanho/metabolismo , Compostos Orgânicos de Estanho/toxicidade , Salinidade
9.
Int J Mol Sci ; 23(17)2022 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-36077294

RESUMO

Soil salinity is a major constraint that affects plant growth and development. Rice is a staple food for more than half of the human population but is extremely sensitive to salinity. Among the several known mechanisms, the ability of the plant to exclude cytosolic Na+ is strongly correlated with salinity stress tolerance in different plant species. This exclusion is mediated by the plasma membrane (PM) Na+/H+ antiporter encoded by Salt Overly Sensitive (SOS1) gene and driven by a PM H+-ATPase generated proton gradient. However, it is not clear to what extent this mechanism is operational in wild and cultivated rice species, given the unique rice root anatomy and the existence of the bypass flow for Na+. As wild rice species provide a rich source of genetic diversity for possible introgression of abiotic stress tolerance, we investigated physiological and molecular basis of salinity stress tolerance in Oryza species by using two contrasting pairs of cultivated (Oryza sativa) and wild rice species (Oryza alta and Oryza punctata). Accordingly, dose- and age-dependent Na+ and H+ fluxes were measured using a non-invasive ion selective vibrating microelectrode (the MIFE technique) to measure potential activity of SOS1-encoded Na+/H+ antiporter genes. Consistent with GUS staining data reported in the literature, rice accessions had (~4-6-fold) greater net Na+ efflux in the root elongation zone (EZ) compared to the mature root zone (MZ). Pharmacological experiments showed that Na+ efflux in root EZ is suppressed by more than 90% by amiloride, indicating the possible involvement of Na+/H+ exchanger activity in root EZ. Within each group (cultivated vs. wild) the magnitude of amiloride-sensitive Na+ efflux was higher in tolerant genotypes; however, the activity of Na+/H+ exchanger was 2-3-fold higher in the cultivated rice compared with their wild counterparts. Gene expression levels of SOS1, SOS2 and SOS3 were upregulated under 24 h salinity treatment in all the tested genotypes, with the highest level of SOS1 transcript detected in salt-tolerant wild rice genotype O. alta (~5-6-fold increased transcript level) followed by another wild rice, O. punctata. There was no significant difference in SOS1 expression observed for cultivated rice (IR1-tolerant and IR29-sensitive) under both 0 and 24 h salinity exposure. Our findings suggest that salt-tolerant cultivated rice relies on the cytosolic Na+ exclusion mechanism to deal with salt stress to a greater extent than wild rice, but its operation seems to be regulated at a post-translational rather than transcriptional level.


Assuntos
Oryza , Tolerância ao Sal , Amilorida/farmacologia , Regulação da Expressão Gênica de Plantas , Humanos , Íons/metabolismo , Oryza/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Salinidade , Tolerância ao Sal/genética , Sódio/metabolismo , Trocadores de Sódio-Hidrogênio/genética , Trocadores de Sódio-Hidrogênio/metabolismo
10.
Artigo em Inglês | MEDLINE | ID: mdl-36078599

RESUMO

In efforts to improve plant productivity and enhance defense mechanisms against biotic and abiotic stresses, endophytic bacteria have been used as an alternative to chemical fertilizers and pesticides. In the current study, 25 endophytic microbes recovered from plant organs of Triticum aestivum L. (wheat) were assessed for biotic (phyto-fungal pathogens) and abiotic (salinity, drought, and heavy metal) stress tolerance. Among the recovered isolates, BPR-9 tolerated maximum salinity (18% NaCl), drought (15% PEG-6000), and heavy metals (µg mL-1): Cd (1200), Cr (1000), Cu (1000), Pb (800), and Hg (30). Based on phenotypic and biochemical characteristics, as well as 16S rDNA gene sequencing, endophytic isolate BPR-9 was recognized as Priestia aryabhattai (accession no. OM743254.1). This isolate was revealed as a powerful multi-stress-tolerant crop growth promoter after extensive in-vitro testing for plant growth-promoting attributes, nutrient (phosphate, P; potassium, K; and zinc, Zn) solubilization efficiency, extracellular enzyme (protease, cellulase, amylase, lipase, and pectinase) synthesis, and potential for antagonistic activity against important fungal pathogens viz. Alternaria solani, Rhizoctonia solani, Fusarium oxysporum, and Ustilaginoidea virens. At elevated salt levels, increases were noted in indole-3-acetic acid; siderophores; P, K, and Zn-solubilization; ACC deaminase; and ammonia synthesized by Priestia&nbsp;aryabhattai. Additionally, under in-vitro plant bioassays, wheat seedlings inoculated with P.&nbsp;aryabhattai experienced superior growth compared to non-inoculated seedlings in high salinity (0-15% NaCl) environment. Under NaCl stress, germination rate, plant length, vigor indices, and leaf pigments of wheat seedlings significantly increased following P.&nbsp;aryabhattai inoculation. Furthermore, at 2%-NaCl, B.&nbsp;aryabhattai greatly and significantly (p ≤ 0.05) decreased relative leaf water content, membrane damage, and electrolyte leakage compared with the non-inoculated control. Catalase, superoxide dismutase, and peroxidase activity increased by 29, 32, and 21%, respectively, in wheat seedlings exposed to 2% NaCl and inoculated with the bacteria. The present findings demonstrate that endophytic P.&nbsp;aryabhattai strains might be used in the future as a multi-stress reducer and crop growth promoter in agronomically important crops including cereals.


Assuntos
Metais Pesados , Triticum , Bacillus , Salinidade , Tolerância ao Sal/genética , Plântula , Cloreto de Sódio
11.
Water Res ; 223: 118982, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36058098

RESUMO

Anaerobic technology is extensively applied in the treatment of industrial organic wastewater, but high salinity always triggers microbial cell dehydration, causing the failure of the anaerobic process. In this work, betaine, one kind of compatible solutes which could balance the osmotic pressure of anaerobic biomass, was exogenously added for enhancing the anaerobic reduction of nitrobenzene (NB) at high salinity. Only 100 mg L-1 betaine dosing could significantly promote the removal efficiency of NB within 35 h at 9% salinity (36.92 ± 4.02% without betaine and 72.94 ± 6.57% with betaine). The relieving effects on salt stress could be observed in the promotion of more extracellular polymeric substances (EPS) secretion with betaine addition. Additionally, the oxidation-reduction potential (ORP), as well as the electron transfer system (ETS) value, was increased with betaine addition, which was reflected in the improvement of system removal efficiency and enzyme activity. Microbial community analysis demonstrated that Bacillus and Clostridiisalibacter which were positively correlated with the stability of the anaerobic process were enriched with betaine addition at high salinity. Metagenomic analysis speculated that the encoding genes for salt tolerance (kdpB/oadA/betA/opuD/epsP/epsH) and NB degradation (nfsA/wrbA/ccdA/menC) obtained higher relative abundance with betaine addition under high salt environment, which might be the key to improving salt tolerance of anaerobic biomass. The long-term assessment demonstrated that exogenous addition betaine played an important role in maintaining the stability of the anaerobic system, which would be a potential strategy to achieve a high-efficiency anaerobic process under high salinity conditions.


Assuntos
Betaína , Salinidade , Anaerobiose , Nitrobenzenos , Águas Residuárias
12.
BMC Plant Biol ; 22(1): 453, 2022 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-36131250

RESUMO

BACKGROUND: Alhagi sparsifolia (Camelthorn) is a leguminous shrub species that dominates the Taklimakan desert's salty, hyperarid, and infertile landscapes in northwest China. Although this plant can colonize and spread in very saline soils, how it adapts to saline stress in the seedling stage remains unclear so a pot-based experiment was carried out to evaluate the effects of four different saline stress levels (0, 50, 150, and 300 mM) on the morphological and physio-biochemical responses in A. sparsifolia seedlings. RESULTS: Our results revealed that N-fixing A. sparsifolia has a variety of physio-biochemical anti-saline stress acclimations, including osmotic adjustments, enzymatic mechanisms, and the allocation of metabolic resources. Shoot-root growth and chlorophyll pigments significantly decreased under intermediate and high saline stress. Additionally, increasing levels of saline stress significantly increased Na+ but decreased K+ concentrations in roots and leaves, resulting in a decreased K+/Na+ ratio and leaves accumulated more Na + and K + ions than roots, highlighting their ability to increase cellular osmolarity, favouring water fluxes from soil to leaves. Salt-induced higher lipid peroxidation significantly triggered antioxidant enzymes, both for mass-scavenging (catalase) and cytosolic fine-regulation (superoxide dismutase and peroxidase) of H2O2. Nitrate reductase and glutamine synthetase/glutamate synthase also increased at low and intermediate saline stress levels but decreased under higher stress levels. Soluble proteins and proline rose at all salt levels, whereas soluble sugars increased only at low and medium stress. The results show that when under low-to-intermediate saline stress, seedlings invest more energy in osmotic adjustments but shift their investment towards antioxidant defense mechanisms under high levels of saline stress. CONCLUSIONS: Overall, our results suggest that A. sparsifolia seedlings tolerate low, intermediate, and high salt stress by promoting high antioxidant mechanisms, osmolytes accumulations, and the maintenance of mineral N assimilation. However, a gradual decline in growth with increasing salt levels could be attributed to the diversion of energy from growth to maintain salinity homeostasis and anti-stress oxidative mechanisms.


Assuntos
Antioxidantes , Fabaceae , Antioxidantes/metabolismo , Catalase/metabolismo , Clorofila/metabolismo , Fabaceae/metabolismo , Glutamato Sintase/metabolismo , Glutamato Sintase/farmacologia , Glutamato-Amônia Ligase/metabolismo , Peróxido de Hidrogênio/metabolismo , Íons/metabolismo , Nitrogênio/metabolismo , Prolina/metabolismo , Salinidade , Plântula/metabolismo , Solo , Açúcares/metabolismo , Superóxido Dismutase/metabolismo , Água/metabolismo
13.
Sci Rep ; 12(1): 15167, 2022 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-36071137

RESUMO

This research introduces a new combined modelling approach for mapping soil salinity in the Minab plain in southern Iran. This study assessed the uncertainty (with 95% confidence limits) and interpretability of two deep learning (DL) models (deep boltzmann machine-DBM) and a one dimensional convolutional neural networks (1DCNN)-long short-term memory (LSTM) hybrid model (1DCNN-LSTM) for mapping soil salinity by applying DeepQuantreg and game theory (Shapely Additive exPlanations (SHAP) and permutation feature importance measure (PFIM)), respectively. Based on stepwise forward regression (SFR)-a technique for controlling factor selection, 18 of 47 potential controls were selected as effective factors. Inventory maps of soil salinity were generated based on 476 surface soil samples collected for measuring electrical conductivity (ECe). Based on Taylor diagrams, both DL models performed well (RMSE < 20%), but the 1DCNN-LSTM hybrid model performed slightly better than the DBM model. The uncertainty range associated with the ECe values predicted by both models estimated using DeepQuantilreg were similar (0-25 dS/m for the 1DCNN-LSTM hybrid model and 2-27 dS/m for DBM model). Based on the SFR and PFIM (permutation feature importance measure)-a measure in game theory, four controls (evaporation, sand content, precipitation and vertical distance to channel) were selected as the most important factors for soil salinity in the study area. The results of SHAP (Shapely Additive exPlanations)-the second measure used in game theory-suggested that five factors (evaporation, vertical distance to channel, sand content, cation exchange capacity (CEC) and digital elevation model (DEM)) have the strongest impact on model outputs. Overall, the methodology used in this study is recommend for applications in other regions for mapping environmental problems.


Assuntos
Aprendizado Profundo , Solo , Teoria do Jogo , Salinidade , Areia , Incerteza
14.
Environ Manage ; 70(4): 581-592, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35920927

RESUMO

Across coastal areas of the northern Gulf of Mexico, the Deepwater Horizon oil spill resulted in significant ecological injury, and over 8 billion USD directed to restoration activities. Oyster restoration projects were implemented with regional goals of restoring oyster abundance, spawning stock, and population resilience. Measuring regional or large-scale ecosystem restoration outcomes challenges traditional project-specific monitoring and outcome reporting. We examine the outcomes of oyster restoration at the project-level and discuss potential pathways to measure progress toward region-level goals. An estimated 15 km2 of oyster habitat was restored across 11 different estuaries with 62 individual reef footprints created, ranging in size from ~0.2 to 1.45 km2. Individual sites were distributed across the salinity gradient, and all reefs were subtidal. One-year post-restoration, mean total oyster density across all sites was 53.0 ± 60.7 ind m-2 of which 38.4 ± 42.2 ind m-2 were adult (>25 mm shell height) oysters. Recent data (2018/2019) available for all sites indicates reduced densities of total oysters (44.6 ± 70.9 ind m-2) and adult oysters (14.6 ± 21.6 ind m-2). These data provide insight into project specific outcomes, suggesting an overall enhancement in oyster abundance compared to pre-restoration, but fall short of informing outcomes at the regional-level that incorporate cumulative effects on adjacent and connected reef populations, or inform overall resiliency of the regional oyster resource. Developing regional outcome benchmarks that enable assessment of cumulative and synergistic impacts of individual projects may benefit from broader spatial and temporal monitoring requirements that can better inform development of regional tools or models. Such tools would enable cumulative effects analyses examining net resource change, resilience and assess impacts of restoration activities on regional resource status.


Assuntos
Ostreidae , Poluição por Petróleo , Animais , Ecossistema , Estuários , Salinidade
15.
J Environ Manage ; 321: 115922, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36027730

RESUMO

Benzo [a]pyrene (BaP) is a type of high-molecular-weight polycyclic aromatic hydrocarbons (PAHs) with potent carcinogenicity; however, there are limited studies on its degradation mechanism. Here, a strain of Pontibacillus sp. HN14 with BaP degradation ability was isolated from mangrove sediments in Dongzhai Port, Hainan Province. Our study showed that biodegradation efficiencies reached 42.15% after Pontibacillus sp. HN14 was cultured with 20 mg L-1 BaP as the sole carbon source for 25 days and still had degradability of BaP at a 25% high salinity level. Moreover, 9,10-dihydrobenzo [a]pyrene-7(8H)-one, an intermediate metabolite, was detected during BaP degradation in the HN14 strain. Genome analysis identified a gene encoding the CYP102(HN14) enzyme. The results showed that the E. coli strain with CYP102(HN14) overexpression could transfer BaP to 9,10-dihydrobenzo [a]pyrene-7(8H)-one with a conversion rate of 43.5%, indicating that CYP102(HN14) played an essential role in BaP degradation in Pontibacillus sp. HN14. Thus, our results provide a novel BaP biodegradation molecule, which could be used in BaP bioremediation in high salinity conditions. This study is the first to show that CYP102(HN14) had the BaP oxidization ability in bacteria. CYP102(HN14) could be essential in removing PAHs in saline-alkali soil and other high salt environments through enzyme immobilization.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos , Benzo(a)pireno/metabolismo , Biodegradação Ambiental , Escherichia coli , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Pirenos/metabolismo , Salinidade
16.
Bioresour Technol ; 362: 127815, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36031126

RESUMO

This study evaluated the combined impact of salinity (2.5, 13, and 19.3 g NaCl/L) and inoculum pretreatment (acid/alkali) on the genomic and metabolic profiles of mesophilic fermentative bacteria for hydrogen (H2) production from food waste. Experimental results revealed that acid-treated inoculum showed the highest H2 yield (201.12 ± 13.84 mL H2/g of volatile solids added) under medium salinity levels compared to other experimental conditions. A 7-56% increase in H2 yield was observed for pretreated inoculum than untreated inoculum. Genomic analysis and metabolic pattern revealed that the H2 production was mainly through Clostridial-type fermentation under medium to high salinity levels, whereas Enterococcus-type fermentation under low salinity levels. Further, the genomic analysis uncovered that phyla Firmicutes (69.71-96.81%) and genus Clostridium sensu stricto 1 (33.28-94.04%) dominated during the exponential gas production phase. Overall, this study showed the significance of inoculum pretreatment for the bioconversion of food waste at different salinity levels.


Assuntos
Alimentos , Eliminação de Resíduos , Álcalis/metabolismo , Reatores Biológicos , Clostridium/genética , Clostridium/metabolismo , Fermentação , Hidrogênio/metabolismo , Salinidade , Esgotos
17.
Langmuir ; 38(33): 10313-10330, 2022 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-35952366

RESUMO

Researchers are looking for new, clean, and accessible sources of energy due to rising global warming caused by the usage of fossil fuels and the irreversible harm that this does to the environment. Water salinity is one of the newest and most accessible renewable energy sources, which has sparked a lot of interest. Reverse electrodialysis (RED) has been utilized in the past to turn saline water into electricity. NRED, a reverse electrodialysis method utilizing nanofluidics, has gained popularity as nanoscale research advances. Developing and evaluating NRED systems is time-consuming and expensive due to the method's novelty; thus, modeling is required to identify the best locations for implementation and to comprehend its workings. In this work, we examined the influence of bipolar soft layer and nanochannel geometry on ion transfer and power production simultaneously. To achieve this, the two trumpet and cigarette geometries were coated with a bipolar soft layer so that both negative (type (I)) and positive (type (II)) charges could be positioned in the nanochannel's small aperture. After that, at steady state conditions, the Poisson-Nernst-Planck (PNP) and Navier-Stokes (NS) equations were solved concurrently. The findings revealed that altering the nanochannel coating from type (I) to type (II) alters the channel's selectivity from cations to anions. An approximately 22-fold improvement in energy conversion efficiency was achieved by raising the concentration ratio from 10 to 100 for the type (I) trumpet nanochannel. Type (I) cigarette geometry is advised for maximum power output at low and medium concentration ratios, whereas type (I) trumpet geometry is recommended for the maximum power production at high concentration ratios.


Assuntos
Eletricidade , Salinidade
18.
PLoS One ; 17(8): e0252695, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36007076

RESUMO

The Amazon Continental Shelf (ACS) is a complex habitat that receives a large annual freshwater discharge into the ocean, producing a superficial plume and carrying with it large amounts of nutrients to the continental shelf along thousands of kilometers while sustaining high biodiversity in the estuary-ocean continuum. For the first time, this study monitored six sites in a wide transect with approximately 240 km radius on the ACS every 2-4 months. The objectives were (1) to analyze the composition of larval Brachyuran crabs and (2) to predict the importance of environmental parameters (temperature, salinity and chlorophyll-a) in structuring their abundance. A total of 17,759 larvae identified were distributed in 8 families and 24 taxa. The water salinity was the best predictor of larval distribution. The statistical models used indicated that Panopeidae and Portunidae larvae are more frequent and more likely to occur in shallow water layers, while Calappidae occur in deeper layers, and Grapsidae, Ocypodidae, Sesarmidae, Pinnotheridae and Leucosiidae occur similarly in both strata. The larval dispersal extent varies among families and throughout the year while the groups are distributed in different salinities along the platform. The probability of occurrence of Portunidae is higher in ocean water (≥ 33.5); Grapsidae, Panopeidae, and Pinnotheridae is higher in intermediate and ocean salinity waters (25.5 to 33.5); Ocypodidae, Sesarmidae and Calappidae is higher in estuarine and intermediate salinity waters (5 to 25.5), whereas Leucosiidae, euryhaline, occur in all salinities (5 to 33.5). Furthermore, the Amazon River seasonal flow and plume movement throughout the year not only regulate the larval distribution and dispersion of estuarine species but are also fundamental for the ACS species, providing the necessary nutrient input for larval development in the region.


Assuntos
Braquiúros , Animais , Estuários , Humanos , Larva , Salinidade , Água
19.
Genes (Basel) ; 13(8)2022 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-36011261

RESUMO

Although salinity stress is one of the principal abiotic stresses affecting crop yield, a suitable concentration of NaCl has proven to be useful for increasing crop quality. This study used low salinity (34 mmol/L NaCl) and high salinity (85 mmol/L) to cultivate purple sweetpotato. Using transcriptomics and metabolomics to profile the pathway indicated that glycometabolism, secondary metabolite biosynthesis and the starch catabolic process were the significant pathways under the salinity stress. Further research showed that purple sweetpotato could regulate genes related to the regulation of the cellular Na+, K+, and other ions concentration in response to the low salinity tolerance, but loses this ability under high salinity. Meanwhile, under low salinity, the activity of antioxidant enzymes and their related gene expression are maintained at a high level. The low salinity influences the monosaccharide composition as well as the content and regulation of genes related to starch synthesis. Quality analysis showed that the low salinity could increase the starch content and influence the amylopectin biosynthesis. It suggested that low salinity promotes substance accumulation. High salinity could increase the anthocyanins biosynthesis and low salinity had a significant impact on phenolic acid and flavonol. Finally, the gene expression levels also prove the low salinity could change the composition and content level of the purple sweetpotato. This study showed that an appropriate concentration of NaCl can be used as an elicitor for application in purple sweetpotato planting.


Assuntos
Ipomoea batatas , Adaptação Psicológica , Antocianinas/genética , Antocianinas/metabolismo , Ipomoea batatas/genética , Salinidade , Cloreto de Sódio/metabolismo , Cloreto de Sódio/farmacologia , Amido/metabolismo
20.
Aquat Toxicol ; 250: 106263, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35939883

RESUMO

Marine-coastal systems have been increasingly exposed to multiple stressors, including anthropogenic pollution and variations of Climate Change (CC) related factors, whose coexistence could create associated environmental and ecotoxicological risks. Among emergent stressors, 4-methylbenzylidenecamphor (4-MBC) and benzophenone-3 (BP-3) UV-filters are compounds widely used in increasing consumer products, resulting in their ubiquity in aquatic environments and possible pressing challenges on gamete susceptibility. Since most marine invertebrates reproduce by external fertilization, after spawning, gametes may be exposed to several pressures, affecting reproductive success and outcome. The present study focuses on the spermiotoxicity of the environmentally relevant UV-filters 4-MBC and BP-3 combined with salinity shifts, as potential modulators of their harmful effects. For this, Mytilus galloprovincialis male gametes were exposed in vitro to environmentally relevant and slightly higher concentrations (1, 10 and 100 µg/L) of 4-MBC or BP-3 under three different salinities (S 20, 30 and 40). Sperm quality endpoints associated with oxidative status, viability, motility, kinetics, and genotoxicity were evaluated. Similarities and differences in sperm responses among all conditions were highlighted by principal coordinates analysis (PCO). Results showed that salinity acting alone posed greater sperms impairments at the lowest (20) and highest (40) tested levels. When salinity acts as a co-varying stressor, salinity-dominant interactive effects resulted evident, especially for 4-MBC at S 40 and BP-3 at S 20. These findings were pointed out as the worst exposure conditions for M. galloprovincialis sperms, since caused major toxicological effects in terms of: (I) oxidative stress, sperm structural impairments, motility and kinetic alterations in 4-MBC-exposed sperms; (II) DNA damage, compromised mitochondrial activity and hyperactivation in BP-3-exposed ones. Overall, it stands out that salinity influences UV-filter toxicological pathways and, thereby, the potential environmental risk of these contaminants on M. galloprovincialis male gametes, especially in an expected salinity stress scenario.


Assuntos
Mytilus , Poluentes Químicos da Água , Animais , Masculino , Salinidade , Sêmen/química , Sêmen/metabolismo , Espermatozoides/metabolismo , Poluentes Químicos da Água/toxicidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...