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Castanea sativa Miller, a high-valuable crop for Mediterranean countries, is facing frequent and prolonged periods of heat and drought, severely affecting chestnut production. Aiming to tackle this problem, this study unraveled the influence of mycorrhizal association with the fungi Paxillus involutus (Batsch) on young chestnut plants' responses to combined heat (42 °C; 4 h/day) and drought (no irrigation until soil moisture reached 25%) over 21 days of stress exposure. Heat stress had no harmful effects on growth, photosynthesis, nor induced oxidative stress in either mycorrhizal (MR) or non-mycorrhizal (NMR) chestnut plants. However, drought (alone or combined) reduced the growth of NMR plants, affecting water content, leaf production, and foliar area, while also hampering net CO2 assimilation and carbon relations. The mycorrhizal association, however, mitigated the detrimental effects of both stresses, resulting in less susceptibility and fewer growth limitations in MR chestnut plants, which were capable of ensuring a proper carbon flow. Evaluation of the oxidative metabolism revealed increased lipid peroxidation and hydrogen peroxide levels in NMR plants under water scarcity, supporting their higher susceptibility to stress. Conversely, MR plants activated defense mechanisms by accumulating antioxidant metabolites (ascorbate, proline and glutathione), preventing oxidative damage, especially under the combined stress. Overall, drought was the most detrimental condition for chestnut growth, with heat exacerbating stress susceptibility. Moreover, mycorrhizal association with P. involutus substantially alleviated these effects by improving growth, water relations, photosynthesis, and activating defense mechanisms. Thus, this research highlights mycorrhization's potential to enhance C. sativa resilience against climate change, especially at early developmental stages.
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The Mediterranean basin is highly susceptible to climate change, with soil salinization and the increase in average temperatures being two of the main factors affecting crop productivity in this region. Following our previous studies on describing the detrimental effects of heat and salt stress co-exposure on tomato plants, this study aimed to understand if substrate supplementation with a combination of arbuscular mycorrhizal fungi (AMF) and biochar could mitigate the negative consequences of these stresses. Upon 21 days of exposure, stressed tomato plants grown under supplemented substrates showed increased tolerance to heat (42 °C for 4 h/day), salt (100 mM NaCl), and their combination, presenting increased biomass and flowering rate. The beneficial effects of AMF and biochar were associated with a better ionic balance (i.e. lower sodium accumulation and higher uptake of calcium and magnesium) and increased photosynthetic efficiency. Indeed, these plants presented higher chlorophyll content and improved CO2 assimilation rates. Biochemical data further supported that tomato plants grown with AMF and biochar were capable of efficiently modulating their defence pathways, evidenced by the accumulation of proline, ascorbate, and glutathione, coupled with a lower dependency on energy-costly enzymatic antioxidant players. In summary, the obtained data strongly point towards a beneficial role of combined AMF and biochar as sustainable tools to improve plant growth and development under a climate change scenario, where soil salinization and heat peaks often occur together.
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Carbón Orgánico , Micorrizas , Estrés Salino , Solanum lycopersicum , Micorrizas/fisiología , Solanum lycopersicum/fisiología , Solanum lycopersicum/microbiología , Estrés Salino/fisiología , CalorRESUMEN
The equilibrium of the marine ecosystem is currently threatened by several constraints, among which climate change and anthropogenic activities stand out. Indeed, these factors favour the growth of macroalgae, which sometimes end up stranded on the beaches at the end of their life cycle, forming what is known as beach wrack. Despite its undeniable important ecological role on beaches, as it is an important source of organic matter (OM), and provides food and habitat for several invertebrates, reptiles, small mammals, and shorebirds, the overaccumulation of beach wrack is often associated with the release of greenhouse gases, negatively impacting tourist activities, and generating economic expenses for its removal. Although currently beach wrack is mainly treated as a waste, it can be used for numerous potential applications in distinct areas. This review aimed at providing a solid point of view regarding the process of wrack formation, its spatiotemporal location, as well as its importance and risks. It also contains the current advances of the research regarding sustainable alternatives to valorise this organic biomass, that range from bioenergy production to the incorporation of wrack in agricultural soils, considering a circular economy concept. Although there are some concerns regarding wrack utilisation, from its variable availability to a possible soil contamination with salts and other contaminants, this review comprises the overall beneficial effects of the incorporation of this residue particularly in the organic agricultural model, strengthening the conversion of this wasted biomass into a valuable resource.
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Ecosistema , Algas Marinas , Animales , Agricultura , Biomasa , Suelo/química , MamíferosRESUMEN
The occurrence of drought in soils, particularly in those contaminated by metals, poses a current threat to crops, as these factors can interact and induce unique stress responses. Therefore, this study mainly focused on understanding the crosstalk between drought and copper (Cu) stress in the physiology of the barley (Hordeum vulgare L.) plant. Using a bifactorial experimental design, seedlings were grown in a natural soil under the following treatments: plants continuously irrigated in uncontaminated soil for 14 days (control); plants continuously irrigated in Cu-contaminated soil (115 mg Cu kg-1) for 14 days (Cu); plants only irrigated during the initials 7 days of growth in uncontaminated soil (drought); plants co-exposed to Cu and drought (combined). After 14 days of growth, the results revealed that drought prevented Cu bioaccumulation in barley roots, which were still severely affected by the metal, both individually and in combination with the water deficit. Furthermore, individual and combined exposure to these stressors resulted in impaired photosynthetic performance in barley plants. Despite the increased activation of enzymatic and non-enzymatic antioxidant defence mechanisms, particularly in the green organs, the plants co-exposed to both stress factors still showed higher oxidative damage, severely impacting biomass production.
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Hordeum , Contaminantes del Suelo , Sequías , Plantas , Metales , Cobre/toxicidad , Suelo , Contaminantes del Suelo/toxicidadRESUMEN
Abiotic stress combinations, such as high temperatures and soil/water salinization, severely threaten crop productivity worldwide. In this work, an integrative insight into the photosynthetic metabolism of tomato plants subjected to salt (100 mM NaCl) and/or heat (42 °C; 4 h/day) was performed. After three weeks, the stress combination led to more severe consequences on growth and photosynthetic pigments than the individual stresses. Regarding the photochemical efficiency, transcript accumulation and protein content of major actors (CP47 and D1) were depleted in all stressed plants, although the overall photochemical yield was not negatively affected under the co-exposure. Gas-exchange studies revealed to be mostly affected by salt (single or combined), which harshly compromised carbon assimilation. Additionally, transcript levels of stress-responsive genes (e.g., HsfA1 and NHX2) were differentially modulated by the single and combined treatments, suggesting the activation of stress-signature responses. Overall, by gathering an insightful overview of the main regulatory hub of photosynthesis, we show that the impacts on the carbon metabolism coming from the combination of heat and salinity, two major conditioners of crop yields, were not harsher than those of single stresses, indicating that the growth impairment might be attributed to a proficient distribution of resources towards defense mechanisms.
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Solanum lycopersicum , Solanum lycopersicum/genética , Calor , Salinidad , Fotosíntesis/fisiología , Estrés Fisiológico , Cloruro de Sodio , Clorofila/metabolismoRESUMEN
BACKGROUND: Fluoride varnish (FV) is widely recommended for caries prevention in preschool children, despite its anticaries benefits being uncertain and modest. Dentists often report using clinical practice guidelines (CPGs) as a source of scientific information. AIM: To identify and analyze recommendations for clinical practice on the use of FV for caries prevention in preschool children and to assess the methodological quality of the CPG on this topic. DESIGN: Two researchers independently used 12 search strategies and searched the first five pages of Google Search™ and three guideline databases for recommendations freely available to health professionals on the use of FV for caries prevention in preschoolers. Then, they retrieved and recorded recommendations that met the eligibility criteria and extracted the data. A third researcher resolved disagreements. Each included CPG was appraised using the AGREE II instrument. RESULTS: Twenty-nine documents were included. Recommendations varied according to age, patients' caries risk, and application frequency. Of the six CPGs, only one scored above 70% in the AGREE II overall assessment. CONCLUSION: Recommendations on the use of FV lacked scientific evidence, and CPGs were of poor quality. Application of FV is widely recommended despite recent evidence showing an uncertain, modest, and possibly not clinically relevant anticaries benefit. Dentists should be aware that it is necessary to critically appraise CPGs since they may be of poor quality.
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Caries Dental , Fluoruros , Humanos , Preescolar , Fluoruros Tópicos/uso terapéutico , Cariostáticos/uso terapéutico , Susceptibilidad a Caries Dentarias , Caries Dental/prevención & control , Caries Dental/tratamiento farmacológicoRESUMEN
ABSTRACT Objective: To assess global trends in the publication of studies investigating the association between ankyloglossia and breastfeeding. Material and Methods: An electronic search was performed in the Scopus database without restrictions. Observational studies and clinical trials were included. Bibliometric indices such as publication year, authors, co-authors, journals, field of knowledge, countries, and the most cited keywords were analyzed using the VOSviewer program. Results: The search retrieved 350 studies, and 68 were selected. The first article was published in 2000 in the United States. The United States presented the highest number of publications (n=21), followed by Brazil (n=9) and the United Kingdom (n=9). An increase in publications on this theme was observed in 2013; 2021 was the year with the highest number of publications (n=14). The most common word was "frenulum". The authors with the highest number of publications were Botze and Dollbert from Israel (n=3), Ghaheri, and Mace from the United States (n=3). Among the journals, "Breastfeeding Medicine" presented the highest number of publications (n=7), followed by the "International Journal of Pediatric Otorhinolaryngology" (n=6), "CODAS" (n=5), "Journal of Human Lactation" (n=4) and "Pediatrics" (n=3); the latter published the top-cited studies, with 412 citations. Conclusion: There has been an increase in recent articles evaluating the correlation between ankyloglossia and breastfeeding, indicating the growing interest of researchers in this field.
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Lactancia Materna/tendencias , Bibliometría , Anquiloglosia , Frenillo LingualRESUMEN
Abstract Objective: To summarize data of clinical trials that used silver diamine fluoride (SDF) to prevent and treat caries lesions and dentinal hypersensitivity. Material and Methods: Six electronic databases were searched in May 2022. The concentration of SDF, type of usage (alone/combined), dentition, anterior/posterior teeth, tooth region, dental tissue, number of the treated surfaces, the intervention environment, participants' age, frequency and duration of SDF application, purpose, and outcome were the extracted variables. The type of study, year of publication, authors, journals, and country were also investigated. Results: From 8860 articles, S3 were selected. Most were randomized (n=38), that applied 38% SDF (n=43), alone (n=44), on multiple surfaces (n=44), only in dentin (n=36), of the crown (n=46) of anterior and posterior (n=36) primary teeth (n=39). The studies were preferably carried out outside the clinic (n=3l), only in children (n=33), with reapplication of SDF (n=30), but did not inform the duration of application (n= 19). SDF was most used to treat (n=46) only caries lesions (n=50). They were published between 2001 and 2022, mainly in the Journal of Dentistry (n=10). China (n=19) and Lo E.GM (n=19) were the countries and authors that published the most, respectively. Conclusion: The silver diamine fluoride 38% alone was most used to treat caries lesions in the dentin of the crown of all primary teeth, preferably applied on multiple surfaces, requiring re application, and outside the clinic.
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Cariostáticos/química , Sensibilidad de la Dentina/etiología , Caries Dental/etiología , Minería de DatosRESUMEN
Allelopathy, the inhibition of neighbouring plant growth by certain plants, can be particularly useful if applied in a targeted way for weed management. So, this study aimed to assess and characterize the herbicidal activity of fresh and dried leaves from young Eucalyptus globulus Labill. trees applied as a soil amendment. For this, fresh and dried leaves (FL and DL, respectively) were incorporated into the soil at different concentrations (0, 1, 5, and 10% w/w), where Portulaca oleracea L. seeds were sown. After 5 weeks of exposure, results revealed that the soil incorporation of DL at 10% (w/w) presented the strongest herbicidal properties, inhibiting seed germination by 63% and inducing the loss of cell viability. To unravel the possible mode of action and the main targets at both cellular and subcellular levels, an in vitro experiment was performed. Purslane seeds were sown in a nutritive medium containing different dilutions of an aqueous extract prepared with dried eucalyptus leaves. After 5 days of exposure, germinated seedlings were processed for transmission electron microscopy and histological analyses as well as for reactive oxygen species (ROS) in vivo detection by confocal laser scanning microscopy. Results revealed that the allelochemical release from DL induced ROS overproduction, resulting in the loss of cell integrity and organization, which was characterized by damage to several cellular sub-structures, along with enhanced accumulation of lipid droplets. Overall, the incorporation of DL into the soil can represent a sustainable alternative to reduce synthetic herbicide application and subsequent environmental contamination.
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As available tools for crop disease management are scarce, new, effective, and eco-friendly solutions are needed. So, this study aimed at assessing the antibacterial activity of a dried leaf Eucalyptus globulus Labill. aqueous extract (DLE) against Pseudomonas syringae pv. tomato (Pst), Xanthomonas euvesicatoria (Xeu), and Clavibacter michiganensis michiganensis (Cmm). For this, the inhibitory activity of different concentrations of DLE (0, 15, 30, 45, 60, 75, 90, 105, 120, 135, and 250 g L-1) was monitored against the type strains of Pst, Xeu, and Cmm through the obtention of their growth curves. After 48 h, results showed that the pathogen growth was strongly inhibited by DLE, with Xeu the most susceptible species (15 g L-1 MIC and IC50), followed by Pst (30 g L-1 MIC and IC50), and Cmm (45 and 35 g L-1 MIC and IC50, respectively). Additionally, using the resazurin assay, it was possible to verify that DLE considerably impaired cell viability by more than 86%, 85%, and 69% after Pst, Xeu, and Cmm were incubated with DLE concentrations equal to or higher than their MIC, respectively. However, only the treatment with DLE at 120 g L-1 did not induce any hypersensitive response in all pathogens when treated bacterial suspensions were infiltrated onto tobacco leaves. Overall, DLE can represent a great strategy for the prophylactic treatment of tomato-associated bacterial diseases or reduce the application of environmentally toxic approaches.
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This study aimed to understand the morphophysiological responses and primary metabolism of tomato seedlings subjected to mild levels of nitrogen and/or water deficit (50% N and/or 50% W). After 16 days of exposure, plants grown under the combined deficit showed similar behavior to the one found upon exposure to single N deficit. Both N deficit treatments resulted in a significantly lower dry weight, leaf area, chlorophyll content, and N accumulation but in a higher N use efficiency when compared to control (CTR) plants. Moreover, concerning plant metabolism, at the shoot level, these two treatments also responded in a similar way, inducing higher C/N ratio, nitrate reductase (NR) and glutamine synthetase (GS) activity, expression of RuBisCO encoding genes as well as a downregulation of GS2.1 and GS2.2 transcripts. Interestingly, plant metabolic responses at the root level did not follow the same pattern, with plants under combined deficit behaving similarly to W deficit plants, resulting in enhanced nitrate and proline concentrations, NR activity, and an upregulation of GS1 and NR genes than in CTR plants. Overall, our data suggest that the N remobilization and osmoregulation strategies play a relevant role in plant acclimation to these abiotic stresses and highlight the complexity of plant responses under a combined N+W deficit.
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Agricultural soil degradation is occurring at unprecedented rates, not only as an indirect effect of climate change (CC) but also due to intensified agricultural practices which affect soil properties and biodiversity. Therefore, understanding the impacts of CC and soil degradation on plant physiology is crucial for the sustainable development of mitigation strategies to prevent crop productivity losses. The amino acid proline has long been recognized for playing distinct roles in plant cells undergoing osmotic stress. Due to its osmoprotectant and redox-buffering ability, a positive correlation between proline accumulation and plants' tolerance to abiotic stress has been pointed out in numerous reviews. Indeed, proline quantification is used systematically by plant physiologists as an indicator of the degree of tolerance and a measurement of the antioxidant potential in plants under stressful conditions. Moreover, the exogenous application of proline has been shown to increase resilience to several stress factors, including those related to soil degradation such as salinity and exposure to metals and xenobiotics. However, recent data from several studies often refer to proline accumulation as a signal of stress sensitivity with no clear correlation with improved antioxidant activity or higher stress tolerance, including when proline is used exogenously as a stress reliever. Nevertheless, endogenous proline levels are strongly modified by these stresses, proving its involvement in plant responses. Hence, one main question arises-is proline augmentation always a sign of improved stress resilience? From this perspective, the present review aims to provide a more comprehensive understanding of the implications of proline accumulation in plants under abiotic stress induced by soil degradation factors, reinforcing the idea that proline quantification should not be employed as a sole indicator of stress sensitivity or resilience but rather complemented with further biochemical and physiological endpoints.
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This study aims to perform a broad analysis of the antioxidant (AOX) responses of young tomato plants exposed to single and combined mild nitrogen (N) and water deficits through the evaluation of oxidative biomarkers, non-enzymatic and enzymatic AOX components. 'Micro-Tom' seedlings were subjected to four treatments: control (CTR; 100%N + 100%W), N deficit (N; 50%N), water deficit (W; 50%W), and combined deficits (N + W; 50%N + 50%W). An enhancement of several non-enzymatic and enzymatic components was found in plants subjected to N + W deficit, which presented higher anthocyanins accumulation (up to 103%) as well as higher levels of superoxide dismutase (SOD) transcripts at root level and of ascorbate peroxidase (APX) and catalase (CAT) transcripts at shoot level. This increase in the gene expression was also translated in augmented SOD (up to 202%), APX (up to 155%) and CAT (up to 108%) activity compared to CTR plants and the single deficits. Overall, tomato plants were able to employ defense strategies to cope with this combined deficit, as demonstrated by the higher total AOX capacity (up to 87%) compared to the single deficits, which contributed to the maintenance of their redox homeostasis, with unchanged values of lipid peroxidation and hydrogen peroxide compared with CTR plants.
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Glyphosate (GLY) and flazasulfuron (FLA) are two non-selective herbicides commonly applied together. However, research focused on their single and combined ecotoxicological impacts towards non-target organisms is still inconclusive. Therefore, this study aimed to test their single effects on soil's habitat and retention functions, and to unravel their combined impacts to earthworms and terrestrial plants. For this, ecotoxicological assays were performed with plants (Medicago sativa), oligochaetes (Eisenia fetida) and collembola (Folsomia candida). Soil elutriates were also prepared and tested in macrophytes (Lemna minor) and microalgae (Raphidocelis subcapitata). FLA (82-413 µg kg-1) reduced earthworms' and collembola's reproduction and severely impaired M. sativa growth, being much more toxic than GLY (up to 30 mg kg-1). In fact, the latter only affected plant growth (≥ 9 mg kg-1) and earthworms (≥ 13 mg kg-1), especially at high concentrations, with no effects on collembola. Moreover, only elutriates from FLA-contaminated soils significantly impacted L. minor and R. sucapitata. The experiments revealed that the co-exposure to GLY and FLA enhanced the toxic effects of contaminated soils not only on plants but also on earthworms'. However, such increase in toxicity was dependent on GLY residual concentrations in soils. Overall, this work underpins that herbicides risk assessment should consider herbicides co-exposures, since the evaluation of single exposures is not representative of current phytosanitary practices and of the potential effects under field conditions, where residues of different compounds may persist in soils.
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Artrópodos , Herbicidas , Oligoquetos , Contaminantes del Suelo , Animales , Suelo/química , Contaminantes del Suelo/análisis , Ecosistema , Herbicidas/toxicidad , Plantas , GlifosatoRESUMEN
Aqueous extracts from Eucalyptus globulus leaves contain a wide variety of specialized metabolites, mainly polyphenols and appreciable amounts of volatile compounds, which are responsible for their diverse biological activities, such as antioxidant, antimicrobial, and allelopathic features. For this reason, several studies have been conducted to explore the composition of E. globulus leaf extracts for multiple therapeutic and commercial applications. However, so far, the available bibliographic reports only refer to the chemical composition of extracts prepared with leaves from mature trees, leaving much to clarify about the composition of juvenile eucalyptus leaf extracts. Furthermore, there is no consensus regarding the type of leaves, fresh or dried ones, to be used in the extraction procedure, considering the highest recovery of biologically active compounds. In this sense, this study aimed to characterize the chemical composition of aqueous extracts prepared with fresh and dried leaves from young and mature E. globulus trees. For this, leaf biomass from young and mature E. globulus trees was collected in three distinct places from a forest area, and after oven-drying a portion of the leaves, an extraction in hot water was carried out, followed by GC-MS and HPLC-MS/MS analyses. The results revealed that the maturity of eucalyptus trees and biomass drying significantly influenced the volatile and non-volatile composition of the aqueous extracts. Accordingly, while fresh leaf extracts of young trees had great levels of hydrolysable tannins, extracts prepared with fresh leaves from mature trees presented a wide range of terpenes. When dried leaf material was used, extracts had notorious contents of amino acids derivatives, C13 norisoprenoids, fatty and other organic acids. Overall, this study showed, for the first time, that plant maturity (young vs mature) and pre-processing (fresh vs dried) of foliar biomass of E. globulus trees need to be considered in the preparation of leaf aqueous extracts depending on the desired purposes, since major changes in what regards biologically active compounds were found.
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Aluminum (Al) toxicity limits crops growth and production in acidic soils. Compared to roots, less is known about the toxic effects of Al in leaves. Al subcellular compartmentalization is also largely unknown. Using rye (Secale cereale L.) Beira (more tolerant) and RioDeva (more sensitive to Al) genotypes, we evaluated the patterns of Al accumulation in leaf cell organelles and the photosynthetic and metabolic changes to cope with Al toxicity. The tolerant genotype accumulated less Al in all organelles, except the vacuoles. This suggests that Al compartmentalization plays a role in Al tolerance of Beira genotype. PSII efficiency, stomatal conductance, pigment biosynthesis, and photosynthesis metabolism were less affected in the tolerant genotype. In the Calvin cycle, carboxylation was compromised by Al exposure in the tolerant genotype. Other Calvin cycle-related enzymes, phoshoglycerate kinase (PGK), glyceraldehyde 3-phosphate dehydrogenase (GAPDH), triose-phosphate isomerase (TPI), and fructose 1,6-bisphosphatase (FBPase) activities decreased in the sensitive line after 48 h of Al exposure. Consequentially, carbohydrate and organic acid metabolism were affected in a genotype-specific manner, where sugar levels increased only in the tolerant genotype. In conclusion, Al transport to the leaf and compartmentalization in the vacuoles tolerant genotype's leaf cells provide complementary mechanisms of Al tolerance, protecting the photosynthetic apparatus and thereby sustaining growth.
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Aluminio , Secale , Secale/genética , Secale/metabolismo , Aluminio/toxicidad , Aluminio/metabolismo , Fotosíntesis , Hojas de la Planta , Raíces de Plantas/metabolismoRESUMEN
Avaliaram-se possíveis preditores para a cárie dentária em pré-escolares sem experiência odontológica prévia, que buscaram a clínica de odontopediatria de uma universidade pública. Analisaram-se 191 prontuários, dos quais 87 foram incluídos. Coletaram-se dados demográficos, socioeconômicos, histórico de cárie da mãe, orientação prévia sobre cárie, frequência de escovação, uso de dentifrício fluoretado, consumo de doces/biscoitos e/ou líquidos açucarados, ceo-d e a presença ou ausência de defeitos de desenvolvimento do esmalte. Análises descritivas e de regressão logística binária foram realizadas para investigar quais variáveis prediziam um ceod>0. O modelo múltiplo incluiu consumo de doces/biscoitos, dados socioeconômicos, histórico de cárie na mãe e orientação prévia sobre cárie. Das crianças (2,69±1,18 anos), a maioria (67,8%) apresentava ceod>0 (3,78±3,82), sendo 50,6% meninas e 73,3% da classe baixa. A maioria (56,5%) das mães tinha 12 anos de estudos completos, histórico de cárie (78,6%) e receberam orientação prévia sobre cárie (52,9%). A maior parte (80,6%) escova os dentes pelo menos 2 vezes ao dia, utiliza dentifrício fluoretado (75,9%) e consome líquidos açucarados (90,8%), além de doces/biscoitos (86,9%) entre as refeições. Pertencer à classe baixa aumentou em 7 vezes a chance de ceod>0 (OR=7,354; IC 95%=1,951-27,723), histórico de cárie na mãe em 4 vezes (OR=4,131; IC 95%=1,042-16,369) e consumo de doces/biscoitos em quase 2 vezes (OR=1,786; IC 95%=1,072-2,976). Classe econômica baixa, histórico de cárie da mãe e consumo de doces/biscoitos entre as refeições mostraram-se fatores associados ao ceod>0 nos pacientes sem experiência prévia odontológica de uma clínica de odontopediatria de uma universidade pública.
Possible predictors of dental caries in preschool children without previous dental experience, who sought a pediatric dentistry clinic at a public university, were evaluated. Medical records (n=191) were analyzed; 87 were included. Demographic, socioeconomic data, mother's history of caries, previous orientation on caries, brushing frequency, use of fluoridated toothpaste, consumption of sweets/cookies and/or sugary liquids, dmft and the presence or absence of enamel development defects were collected. Descriptive and binary logistic regression analyzes were performed to investigate which variables predicted a dmft>0. The multiple model included consumption of sweets/cookies, socioeconomic data, mother's history of caries and previous orientation on caries. Of the children (2.69±1.18 years), most (67.8%) had dmft>0 (3.78±3.82), with 50.6% girls and 73.3% from the lower class. Most mothers had completed 12 years of schooling (56.5%), reported history of caries (78.6%) and received previous orientation on caries (52.9%). Most of children brush their teeth at least twice a day (80.6%), use fluoridated toothpaste (75.9%) and consume sugary liquids (90.8%), in addition to consumption of sweets/cookies (86 .9%) among the meals. Belonging to the lower class increased the chance of having dmft>0 by 7 times (OR=7,354; 95% CI=1,951-27,723), mother's history of caries by 4 times (OR=4,131;95% CI=1,042-16,369) and consumption of sweets/cookies by almost twice (OR=1,786;95% CI=1,072-2,976). Low economic class, mother's history of caries and consumption of sweets/cookies between meals were factors associated with dmft>0 in the patients without previous dental experience in a pediatric dentistry clinic at a public university.
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Humanos , Masculino , Femenino , Factores Socioeconómicos , Salud Bucal , Caries Dental/etiología , Higiene Bucal , Clase Social , Estudios Transversales , Estudios Retrospectivos , Esmalte Dental , Conducta AlimentariaRESUMEN
Currently, salinity and heat are two critical threats to crop production and food security which are being aggravated by the global climatic instability. In this scenario, it is imperative to understand plant responses to simultaneous exposure to different stressors and the cross-talk between underlying functional mechanisms. Thus, in this study, the physiological and biochemical responses of tomato plants (Solanum lycopersicum L.) to the combination of salinity (100 mM NaCl) and heat (42 °C; 4 h/day) stress were evaluated. After 21 days of co-exposure, the accumulation of Na+ in plant tissues was superior when salt-treated plants were also exposed to high temperatures compared to the individual saline treatment, leading to the depletion of other nutrients and a harsher negative effect on plant growth. Despite that, neither oxidative damage nor a major accumulation of reactive oxygen species took place under stress conditions, mostly due to the accumulation of antioxidant (AOX) metabolites alongside the activation of several AOX enzymes. Nonetheless, the plausible allocation of resources towards the defense pathways related to oxidative and osmotic stress, along with severe Na toxicity, heavily compromised the ability of plants to grow properly when the combination of salinity and heat was imposed.
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This work aimed to evaluate the potential of Fe2O3 nanoparticles (nano-Fe2O3) to alleviate potentially toxic elements (PTEs) - induced stress in barley plants (Hordeum vulgare L.), focusing on bioaccumulation patterns and on plant growth and redox homeostasis. To achieve this goal, plants grew in two agricultural soils, contaminated by different levels of PTEs, collected from an industrial area, previously amended, or not, with 1% (w/w) nano-Fe2O3. After 14 d of growth, biometric parameters were evaluated, along with the analysis of PTEs bioaccumulation and biochemical endpoints. After exposure to contaminated soils, plant development was greatly affected, as evidenced by significant decreases in root length and biomass production. However, upon co-treatment with nano-Fe2O3, lower inhibitory effects on biometric parameters were observed. Regarding the oxidative damage, both soils led to increases in lipid peroxidation and superoxide anion concentration, though hydrogen peroxide levels were only increased in the most contaminated soil. In general, these changes in the oxidative stress markers were accompanied by an upregulation of different antioxidant mechanisms, whose efficiency was even more powerful upon soil amendment with nano-Fe2O3, thus lowering PTEs-induced oxidative damage. Altogether, the present study revealed that nano-Fe2O3 can protect the growth of barley plants under contaminated soils.