RESUMEN

The genus Nothofagus is one of the most abundant in the subantarctic Patagonian forests. Five species inhabit these ecosystems, three evergreen (Nothofagus betuloides, Nothofagus dombeyi, and Nothofagus nitida) and two deciduous (Nothofagus pumilio and Nothofagus antarctica). This is the first report on the levels of secondary metabolites and the antioxidant capacity of Patagonian tree species growing in natural environments. The aim of this work was to carry out a phytochemical screening, to determine the antioxidant capacity, the sun protection factor, and the α-glucosidase and tyrosinase inhibitory activity of foliar extracts of the five previous species. Besides, Aristotelia chilensis and Berberis microphylla, two species of Patagonian shrubs growing in the same forests, were used as reference. N. dombeyi was the Nothofagus with the best antioxidant capacity. B. microphylla differed from all studied species. Moreover, the Nothofagus was split into two groups. N. betuloides and N. dombeyi are the most similar species to A. chilensis. The α-glucosidase was completely inhibited by all studied extracts. Furthermore, N. antarctica, N.pumilio, and N. nitida inhibited about 70% of the tyrosinase activity. All the results found in this study for the species of the genus Nothofagus support further research on their potential beneficial properties for human health.

Asunto(s)

Antioxidantes/farmacología , Inhibidores Enzimáticos/farmacología , Fitoquímicos/farmacología , Árboles/química , Antioxidantes/química , Antioxidantes/metabolismo , Benzotiazoles/antagonistas & inhibidores , Compuestos de Bifenilo/antagonistas & inhibidores , Chile , Evaluación Preclínica de Medicamentos , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/metabolismo , Bosques , Humanos , Monofenol Monooxigenasa/antagonistas & inhibidores , Monofenol Monooxigenasa/metabolismo , Fitoquímicos/química , Fitoquímicos/metabolismo , Picratos/antagonistas & inhibidores , Especificidad de la Especie , Ácidos Sulfónicos/antagonistas & inhibidores , Árboles/metabolismo , alfa-Glucosidasas/metabolismo

RESUMEN

Pterogyne nitens is commonly known in northeastern Brazil as a lesser-known fast-growing species in the Caatinga biome, which is a difficult place for tree development due to the low natural fertility soils and low availability of water. Due to the importance of expanding information about the anatomical wood properties of Caatinga native species, the aim of this work was to characterize the anatomical elements, to macroscopically describe the wood and make inferences about its possible end-uses. Maceration was performed which enabled measuring fiber dimensions, pore frequency and the following technological indexes: cell wall fraction, slenderness ratio, Runkel index and flexibility coefficient. Histological sections enabled describing the arrangements of the cellular elements in different observation sections and to determine the pore diameter. P. nitens wood has anatomical arrangements characterized by confluent axial parenchyma, being diffuse-porous with the presence of tylosis and heterogeneous/stratified rays (biseriate). The fibers were classified as very short (length 0.81 mm), not flexible and Runkel index 0.82. The pores were few in number with a frequency of 32.9 pores/mm2, distributed in a diffuse format and many were obstructed by tylosis. Based on the anatomical results and considering other technological studies, P. nitens wood is most suitable for charcoal production.

Asunto(s)

Fabaceae/anatomía & histología , Árboles/anatomía & histología , Madera/análisis , Brasil , Carbón Orgánico/química , Ecosistema , Fabaceae/química , Fabaceae/citología , Humanos , Células Vegetales/ultraestructura , Árboles/química , Árboles/citología , Madera/citología

RESUMEN

BACKGROUND: Cacao is important for the economy of many countries in the humid tropics. Its quality is affected when fruits are not collected at the optimal harvest point. The aim of this study was to obtain maturity indices for producers to facilitate the timely harvest and improve the development of fermentation and the sensorial quality of cacao. The growth and respiration processes, and the physicochemical changes during the maturation of three cacao genotypes were determined. Physiological follow-ups measuring fruit length and diameter were performed from 30 days after anthesis to fruit deterioration in the tree. RESULTS: Growth equations were obtained, establishing four maturity stages based on days after anthesis, and fruit length and diameter. Nineteen descriptors were used for the characterization, and through Pearson's correlation and principal component analysis (PCA), five descriptors were identified as representative of the maturity stages of the cacao fruit. PCA results and respiration measurements established that stage 3 presented the highest substrate availability for obtaining good fermentation and quality cacao. This stage showed values between 124 and 197 days after anthesis with lengths between 167.7 and 249.73 mm, and diameters between 64.4 and 95.8 mm, according to the locality. CONCLUSION: Three growth phases of the cacao fruits were established considering days after anthesis. Both the edaphoclimatic conditions and the cacao genotype characteristics influenced this determination. Stage 3 of fruit maturation shows the best physicochemical conditions for good fermentation. © 2021 Society of Chemical Industry.

Asunto(s)

Cacao/metabolismo , Frutas/crecimiento & desarrollo , Cacao/química , Cacao/crecimiento & desarrollo , Frutas/química , Frutas/metabolismo , Oxígeno/metabolismo , Respiración , Árboles/química , Árboles/crecimiento & desarrollo , Árboles/metabolismo

RESUMEN

Forest soils are N2O sources and commonly act as CH4 sinks. This study evaluated the dynamics of the CH4 and N2O fluxes of soils under Eucalyptus plantations and native Cerrado vegetation, as well as possible interactions between environmental factors and fluxes. The study was carried out in the Distrito Federal, Brazil, during 26 months, in three areas: in two stands of the hybrid Eucalyptus urophylla × Eucalyptus grandis, planted in 2011 (E1), and in 2009 (E2) and native Cerrado vegetation (CE). Measurements to determine the fluxes in a closed static chamber were carried out from Oct 2013 to Nov 2015. Soil and climate factors were monitored. During the study period, the mean CH4 fluxes were –22.48, –8.38 and –1.31 μg CH4 m–2 h–1 and the mean N2O fluxes 5.45, 4.85 and 3.85 μg N2O m–2 h–1 from E1, E2 and CE, respectively. Seasonality affected plantations in the studied sites. Cumulative CH4 influxes were calculated (year-1: –1.86 to -0.63 kg ha–1 yr–1; year-2: –1.85 to –1.34 kg ha–1 yr–1). Cumulative N2O fluxes in the three sites were ≤ 0.85 kg ha–1 yr–1. The change in land use from Cerrado to Eucalyptus plantations did not significantly changed regarding greenhouse gases (GHG), compared to the native vegetation. Flux rates of both gases (N2O and CH4) were low. Temporal variations in GHG fluxes and different ages of the stands did not cause significant differences in cumulative annual fluxes.

Asunto(s)

Eucalyptus/química , Gases de Efecto Invernadero , Metano , Árboles/química , Óxido Nitroso , Brasil

RESUMEN

Forest soils are N2O sources and commonly act as CH4 sinks. This study evaluated the dynamics of the CH4 and N2O fluxes of soils under Eucalyptus plantations and native Cerrado vegetation, as well as possible interactions between environmental factors and fluxes. The study was carried out in the Distrito Federal, Brazil, during 26 months, in three areas: in two stands of the hybrid Eucalyptus urophylla × Eucalyptus grandis, planted in 2011 (E1), and in 2009 (E2) and native Cerrado vegetation (CE). Measurements to determine the fluxes in a closed static chamber were carried out from Oct 2013 to Nov 2015. Soil and climate factors were monitored. During the study period, the mean CH4 fluxes were –22.48, –8.38 and –1.31 μg CH4 m–2 h–1 and the mean N2O fluxes 5.45, 4.85 and 3.85 μg N2O m–2 h–1 from E1, E2 and CE, respectively. Seasonality affected plantations in the studied sites. Cumulative CH4 influxes were calculated (year-1: –1.86 to -0.63 kg ha–1 yr–1; year-2: –1.85 to –1.34 kg ha–1 yr–1). Cumulative N2O fluxes in the three sites were ≤ 0.85 kg ha–1 yr–1. The change in land use from Cerrado to Eucalyptus plantations did not significantly changed regarding greenhouse gases (GHG), compared to the native vegetation. Flux rates of both gases (N2O and CH4) were low. Temporal variations in GHG fluxes and different ages of the stands did not cause significant differences in cumulative annual fluxes.(AU)

Asunto(s)

Eucalyptus/química , Metano , Óxido Nitroso , Gases de Efecto Invernadero , Árboles/química , Brasil

RESUMEN

The inflorescence of Musa paradisiaca, known as "banana heart" is a structure that includes flowers and bracts of banana, commonly used as food source worldwide. The aims of this study were (1) to determine the mineral components of Musa paradisiaca and (2) to compare the obtained results with previously reported data of Recommendation Dietary Allowances (RDAs) and edible plant permissible limits set by FAO/WHO. The samples were digested using microwave-assisted equipment, while elemental contents were determined by inductively coupled plasma optical emission spectroscopy (ICP OES). Metal (Mg, Ca, Cr, Ni, Cu, Fe, and Zn) and nonmetal (S and P) contents were detected. According to RDA, the inflorescences could be excellent sources of Mg, P, Cr, Cu, Zn, and Fe for females, males, and pregnant women, all age 31-50 y, as well as children (4-8 y). Bracts are good source of Zn for male and pregnant women and good source of Fe for children. All the samples contained considerable amounts of Mg, Ca, P, Ni, Cu, Zn, and Fe, which were quite low to induce deleterious effects (UL). FAO/WHO limits for edible plants have not yet been established for S, P, Mg, and Ca, but Ni and Zn are below of those limit values. However, Cr and Cu concentrations are higher than the values established for edible plants and may pose a threat to human health. Farmers should be encouraged by government agencies, not only for sustainability of production but also to ensure the storage and trade of banana tree inflorescence.

Asunto(s)

Inflorescencia/química , Micronutrientes/análisis , Musa/química , Nutrientes/análisis , Ingesta Diaria Recomendada , Espectrofotometría Atómica/métodos , Femenino , Humanos , Masculino , Árboles/química

Asunto(s)

Conducta Animal , Conducta Alimentaria , Exudados de Plantas , Animales , Brasil , Callithrix/fisiología , Dieta , Zarigüeyas/fisiología , Procyonidae/fisiología , Roedores/fisiología , Árboles/química

RESUMEN

Periodontitis is an immuno-inflammatory disease, which can lead to tooth loss. This study aimed to investigate the efficacy of Platymiscium floribundum Vog., a Brazilian tree which has been used in folk medicine as an anti-inflammatory agent, in a pre-clinical trial of periodontitis in rats. Periodontitis was induced by placing a sterilized nylon (3.0) thread ligature around the cervix of the second left upper molar of the rats, which received (per os) P. floribundum extract (0.1, 1 or 10 mg/kg) or vehicle 1h before periodontitis-challenge and once daily during 11 days. Treatment with P. floribundum (10mg/kg) decreased alveolar bone loss, MPO activity nitrite/nitrate levels, oxidative stress, TNF-α, IL1-ß, IL-8/CINC-1, and PGE2 gingival levels, and transcription of TNF-α, IL1-ß, COX-2, iNOS, RANK, and RANKL genes, while elevated both BALP serum levels and IL-10 gingival levels. The animals did not show signs of toxicity throughout the experimental course. These findings show that P. floribundum has anti-inflammatory and anti-resorptive properties in a pre-clinical trial of periodontitis, representing an interesting biotechnological tool.

Asunto(s)

Antiinflamatorios/farmacología , Inflamación/tratamiento farmacológico , Periodontitis/tratamiento farmacológico , Extractos Vegetales/farmacología , Sustancias Protectoras/farmacología , Árboles/química , Animales , Femenino , Encía/efectos de los fármacos , Encía/metabolismo , Inflamación/metabolismo , Estrés Oxidativo/efectos de los fármacos , Periodontitis/metabolismo , Hojas de la Planta/química , Ratas , Ratas Wistar , Transcripción Genética/efectos de los fármacos

RESUMEN

One of the most polluted areas in Chile is the Ventanas Industrial Area (VIA; 32.74°S / 71.48°W), which started in 1958 and today comprises around 16 industries in an area of ca. 4 km2. A lack of consistent long-term instrumental records precludes assessing the history of contamination in the area and also limits the evaluation of mitigation actions taken since the late 1980s. Here, we use dendrochemistry as an environmental proxy to analyze environmental changes over several decades at the VIA. We present chemical measurements of tree rings from planted, exotic Cupressus macrocarpa growing near the VIA with 4-year resolution over a period of 52 years (1960-2011). These data provide unprecedented information on regional anthropogenic pollution and are compared with a tree-ring elemental record of 48 years (1964-2011) from the Isla Negra (INE) control site not exposed to VIA emissions. For the 48 years of overlap between both sites, higher concentrations of Zn, V, Co, Cd, Ag, Fe, Cr, and Al were especially registered after the year 2000 at VIA compared to INE for the periods under study. Concentrations of Pb, Cu, As, Fe, Mo, Cr, and Zn increased through time, particularly over the period 1980-1990. Decontamination plans activated in 1992 appear to have had a positive effect on the amount of some elements, but the chemical concentration in the tree rings suggest continued accumulation of pollutants in the environment. Only after several years of implementation of the mitigation measures have some elements tended to decrease in concentration, especially at the end of the evaluated period. Dendrochemistry is a useful tool to provide a long-term perspective of the dynamics of trace metal pollution and represents a powerful approach to monitor air quality variability to extend the instrumental records back in time.

Asunto(s)

Monitoreo del Ambiente/métodos , Contaminación Ambiental/estadística & datos numéricos , Árboles/química , Chile , Industrias

RESUMEN

A thorough understanding of the heritability, genetic correlations and additive and non-additive variance components of tree growth and wood properties is a requisite for effective tree breeding. This knowledge is essential to maximize genetic gain, that is, the amount of increase in trait performance achieved annually through directional selection. Understanding the genetic attributes of traits targeted by breeding is also important to sustain decade-long genetic progress, that is, the progress made by increasing the average genetic value of the offspring as compared to that of the parental generation. In this study, we report quantitative genetic parameters for fifteen growth, wood chemical and physical traits for the world-famous Eucalyptus urograndis hybrid (E. grandis × E. urophylla). These traits directly impact the optimal use of wood for cellulose pulp, paper, and energy production. A population of 1,000 trees sampled in a progeny trial was phenotyped directly or following the development and use of near-infrared spectroscopy calibration models. Trees were genotyped with 33,398 SNPs and 24,001 DArT-seq genome-wide markers and genomic realized relationship matrices (GRM) were used for parameter estimation with an individual-tree additive-dominant mixed model. Wood chemical properties and wood density showed stronger genetic control than growth, cellulose and fiber traits. Additive effects are the main drivers of genetic variation for all traits, but dominance plays an equally or more important role for growth, singularly in this hybrid. GRM´s with >10,000 markers provided stable relationships estimates and more accurate parameters than pedigrees by capturing the full genetic relationships among individuals and disentangling the non-additive from the additive genetic component. Low correlations between growth and wood properties indicate that simultaneous selection for wood traits can be applied with minor effects on genetic gain for growth. Conversely, moderate to strong correlations between wood density and chemical traits exist, likely due to their interdependency on cell wall structure such that responses to selection will be connected for these traits. Our results illustrate the advantage of using genome-wide marker data to inform tree breeding in general and have important consequences for operational breeding of eucalypt urograndis hybrids.

Asunto(s)

Eucalyptus/crecimiento & desarrollo , Eucalyptus/genética , Brasil , Eucalyptus/química , Genoma de Planta , Genotipo , Hibridación Genética , Modelos Genéticos , Fenotipo , Fitomejoramiento/métodos , Polimorfismo de Nucleótido Simple , Carácter Cuantitativo Heredable , Especificidad de la Especie , Espectroscopía Infrarroja Corta , Árboles/química , Árboles/genética , Árboles/crecimiento & desarrollo , Madera/química , Madera/genética , Madera/crecimiento & desarrollo

RESUMEN

Environmental impacts of mining activities are well known, particularly on-site degradation, but long term effects are less known. Mercury content from vegetation samples from a mine dump and surrounding forests was quantified for understanding the fate of this element in the local the environment. The study area, Tlalpujahua, Michoacán, México, has a mining history going back more than 400 years. Including gold and silver extraction by means of mercury amalgamation for 352 years (1554-1906). Mercury was present in all sampled materials. The highest values correspond to wood samples from the mine dump (13.84 ± 3.88 ppm), while wood samples from adjacent forests had 4.3 ± 2.4 ppm, almost twice as much as coniferous needles, shrub leaves and corn seeds (2.2 ± 0.34 ppm). The highest concentration was found for J. deppeana wood (16.05 ± 2.3 ppm). The capacity of accumulating mercury by Juniperus trees when growing on the mine dumps suggests that this species has a potential to be used for biosequestration purposes.

Asunto(s)

Contaminantes Ambientales/análisis , Juniperus/química , Mercurio/análisis , Minería , Monitoreo del Ambiente , Oro , México , Pinus/química , Plata , Árboles/química , Madera/química , Zea mays/química

RESUMEN

Tropical forest leaf albedo (reflectance) greatly impacts how much energy the planet absorbs; however; little is known about how it might be impacted by climate change. Here, we measure leaf traits and leaf albedo at ten 1-ha plots along a 3,200-m elevation gradient in Peru. Leaf mass per area (LMA) decreased with warmer temperatures along the elevation gradient; the distribution of LMA was positively skewed at all sites indicating a shift in LMA towards a warmer climate and future reduced tropical LMA. Reduced LMA was significantly (P < 0.0001) correlated with reduced leaf near-infrared (NIR) albedo; community-weighted mean NIR albedo significantly (P < 0.01) decreased as temperature increased. A potential future 2 °C increase in tropical temperatures could reduce lowland tropical leaf LMA by 6-7 g m-2 (5-6%) and reduce leaf NIR albedo by 0.0015-0.002 units. Reduced NIR albedo means that leaves are darker and absorb more of the Sun's energy. Climate simulations indicate this increased absorbed energy will warm tropical forests more at high CO2 conditions with proportionately more energy going towards heating and less towards evapotranspiration and cloud formation.

Asunto(s)

Cambio Climático , Hojas de la Planta/fisiología , Árboles/fisiología , Clima Tropical , Altitud , Dióxido de Carbono/análisis , Bosques , Calor , Modelos Teóricos , Perú , Hojas de la Planta/química , Árboles/química

RESUMEN

The Brazilian Cerrado is one of the most endangered biomes in the world. We evaluated the sustainability of leaf harvest in one of the most important Cerrado tree species, Stryphnodendron adstringens. The bark of this tree is used as a source of medicinal tannin. Harvesting bark, however, often kills the tree. In a manipulative field experiment, we tested the hypothesis that harvesting leaves, which might serve as an alternative source of tannin, would be less detrimental for tree survival, growth, reproduction, and defense than harvesting bark. In a two-way crossed experimental design, we either clipped 100% of a plant's leaves or applied NPK fertilizer to the soil. Our predictions of the experimental outcomes were based on plant resource and defense theory. Growth was determined by total leaf dry mass production, reproduction by inflorescence and fruit production traits, and defense by total phenolics, hydrolyzable tannins, and condensed tannins. Fertilization had a marginally positive effect on total leaf dry mass. Defoliation had no effect on subsequent leaf production, and most importantly, no plants died as a result of defoliation. We found high tannin amounts in leaves of S. adstringens produced both prior to and subsequent to clipping, further suggesting that leaves could serve as a sustainable alternative source of tannin. After clipping, plants invested more in tannin production and less in reproduction. Our results suggest that leaf harvest may be more sustainable than harvesting of bark in S. adstringens. We suggest the need for further investigation of the medicinal properties of leaf tannins to formulate a viable sustainable management plan for the exploitation of this plant species.

Asunto(s)

Agricultura/métodos , Fabaceae/crecimiento & desarrollo , Hojas de la Planta/crecimiento & desarrollo , Árboles/crecimiento & desarrollo , Brasil , Fabaceae/química , Fertilizantes , Bosques , Frutas/química , Frutas/crecimiento & desarrollo , Inflorescencia/crecimiento & desarrollo , Hojas de la Planta/química , Reproducción , Semillas/química , Semillas/crecimiento & desarrollo , Taninos/análisis , Árboles/química

RESUMEN

The concern about environmental pollution has risen in the last decades because of its effects on human's health. However, evaluation of the exposure to certain pollutants is currently hampered by the availability of past environmental data. Tree rings are an alternative to reconstruct environmental variability of pre-instrumental periods. Nevertheless, this approach has some reported limitations including migration of chemical elements in the tree rings. The aim of this study was to evaluate the distribution of Cd, Cu, Hg, Na, Ni, Pb, Zn in the tree rings of Tipuana tipu (Fabaceae) to aid the reconstruction of past environmental pollution. We sampled trees in the central region of the city of São Paulo, Brazil, and scanned their tree rings using LA-ICP-MS. We used these data to evaluate the temporal trends of chemical elements under investigation. Results show a non-random distribution of these chemical elements within the tree rings, with higher content in the cell-walls of vessels and lower content in the fibers. Sodium was the only element intimately related to the axial parenchyma cells. Due to differences in elemental composition of xylem cells, temporal trends where evaluated using distinct quartiles of data distribution in each tree ring. The first quartile represents the lower content found in fibers and parenchyma, while the third quartile corresponds to the higher content found in vessels. Data from vessels better represent the decreasing trend of Cd, Cu, Pb, and Ni in the last three decades. This reduction is less significant for Na and Zn. Our results highlight the potential to improve the records of environmental pollution using data from different cells. Pronounced reduction in Pb may be attributed to the lead phase-out in gasoline, while the decreasing trend of Cd, Cu, Ni pollution is probably related to increasing efficiency of vehicles and the deindustrialization of São Paulo. Chemical elements are non-randomly distributed in tree rings. Chemical content of vessels cell-walls is a reliable record of metal pollution, which is decreasing in São Paulo.

Asunto(s)

Monitoreo del Ambiente/métodos , Contaminantes Ambientales/análisis , Contaminación Ambiental/estadística & datos numéricos , Metales Pesados/análisis , Árboles/química , Brasil , Contaminación Ambiental/análisis , Humanos , Plomo

RESUMEN

Plant secondary metabolites play important ecological and evolutionary roles, most notably in the deterrence of natural enemies. The classical theory explaining the evolution of plant chemical diversity is that new defences arise through a pairwise co-evolutionary arms race between plants and their specialized natural enemies. However, plant species are bombarded by dozens of different herbivore taxa from disparate phylogenetic lineages that span a wide range of feeding strategies and have distinctive physiological constraints that interact differently with particular plant metabolites. How do plant defence chemicals evolve under such multiple and potentially contrasting selective pressures imposed by diverse herbivore communities? To tackle this question, we exhaustively characterized the chemical diversity and insect herbivore fauna from 31 sympatric species of Amazonian Protieae (Burseraceae) trees. Using a combination of phylogenetic, metabolomic and statistical learning tools, we show that secondary metabolites that were associated with repelling herbivores (1) were more frequent across the Protieae phylogeny and (2) were found in average higher abundance than other compounds. Our findings suggest that generalist herbivores can play an important role in shaping plant chemical diversity and support the hypothesis that chemical diversity can also arise from the cumulative outcome of multiple diffuse interactions.

Asunto(s)

Burseraceae/química , Evolución Molecular , Cadena Alimentaria , Herbivoria , Insectos/fisiología , Metaboloma , Animales , Burseraceae/clasificación , Metabolómica , Modelos Estadísticos , Perú , Filogenia , Árboles/química , Árboles/clasificación

RESUMEN

The reasons why the range size of closely related species often varies significantly have intrigued scientists for many years. Among other hypotheses, species with high trait variation were suggested to occupy more diverse environments, have more continuity in their distributions, and consequently have larger range sizes. Here, using 34 tree species of lowlands tropical rainforest in southern Costa Rica, we explored whether inherent trait variability expressed at the local scale in functional traits is related to the species' total geographical range size. We formed 17 congeneric pairs of one narrow endemic and one widespread species, sampled 335 individuals and measured eight functional traits: leaf area, leaf thickness, leaf dry matter content, specific leaf area, leaf nitrogen content, leaf phosphorus content, leaf nitrogen to phosphorus ratio, and wood specific gravity. We tested whether there are significant differences in the locally expressed variation of individual traits or in multidimensional trait variance between the species in congeneric pairs and whether species' range size could hence be predicted from local trait variability. However, we could not find such differences between widely distributed and narrow range species. We discuss the possible reasons for these findings including the fact that higher trait variability of widespread species may result from successive local adaptations during range expansion and may hence often be an effect rather than the cause of larger ranges.

Asunto(s)

Bosque Lluvioso , Árboles , Variación Biológica Poblacional , Costa Rica , Modelos Lineales , Análisis Multivariante , Fenotipo , Dispersión de las Plantas , Hojas de la Planta/anatomía & histología , Hojas de la Planta/química , Semillas/anatomía & histología , Gravedad Específica , Luz Solar , Árboles/anatomía & histología , Árboles/química , Árboles/genética , Clima Tropical , Madera/química

RESUMEN

The extensive land occupation in Southeast Brazil has resulted in climatic disturbances and environmental contamination by air pollutants, threatening the Atlantic forest remnants that still exist in that region. Based on previous results, we assumed that pioneer tree species are potentially more tolerant against environmental oxidative stress than non-pioneer tree species from that Brazilian biome. We also assumed that reactive oxygen species (ROS) are accumulated in higher proportions in leaves of non-pioneer trees, resulting in changes in the oxidant-antioxidant balance and in more severe oxidative damage at the cellular level than in the leaves of pioneer trees. We tested these hypotheses by establishing the relationship between oxidants (ROS), changes in key antioxidants (among enzymatic and non-enzymatic compounds) and in a lipid peroxidation derivative in their leaves, as well as between ROS accumulation and oscillations in environmental stressors, thus permitting to discuss comparatively for the first time the oxidant-antioxidant balance and the tolerance capacity of tree species of the Atlantic Forest in SE Brazil. We confirmed that the non-pioneer tree species accumulated higher amounts of superoxide and hydrogen peroxide in palisade parenchyma and epidermis, showing a less effective antioxidant metabolism than the pioneer species. However, the non-pioneer species showed differing capacities to compensate the oxidative stress in both years of study, which appeared to be associated with the level of ROS accumulation, which was evidently higher in 2015 than in 2016. We also applied exploratory multivariate statistics, which revealed that the oscillations in these biochemical leaf responses in both functional groups coincided with the oscillations in both climatic conditions and air pollutants, seemingly showing that they had acclimated to the stressful oxidative environment observed and may perpetuate in the disturbed forest remnants located in SE Brazil.

Asunto(s)

Antioxidantes/química , Bosques , Oxidantes/química , Estrés Oxidativo , Árboles/química , Contaminación del Aire , Brasil , Monitoreo del Ambiente , Peroxidación de Lípido , Especies Reactivas de Oxígeno/análisis

RESUMEN

Shade plants of ombrophilous forests are subjected to light-limiting conditions and need toinvest in architectural structures associated with leaf symmetry to increase light capture. This study investigated the leaf architecture of six Araucaria forest tree species with distinct symmetry: Cupania vernalis, Casearia sylvestris, Schinus terebinthifolius, Piper gaudichaudianum, Roupala brasiliensis and Cedrela fissilis. We hypothesized that symmetry, associated with other traits, minimizes self-shading. Asymmetry index, petiole length, total leaf area, leaf angle, internode length and stem diameter were measured. The asymmetry index did not indicate a clear distinction between asymmetric and symmetric leaves. Leaves classified as asymmetric had higher values for the asymmetry index in the median and basal regions of the leaf, while symmetrical leaves had higher values in the apical region. The results also indicated an adjustment among structural leaf traits that facilitated a three-dimensional organization that produced an advantageous arrangement for light capture, which seems to be a response to selective pressure by the heterogeneous light conditions of the ombrophilous forest understory.

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Nas florestas ombrófilas, as plantas de sombra estão sujeitas a condições limitantes de luz enecessitam investir em atributos estruturais associados à simetria foliar para maximizar a captura da luz. Esse estudo investigou a arquitetura foliar de seis espécies arbóreas (Cupania vernalis, Casearia sylvestris, Schinus terebinthifolius, Piper gaudichaudianum, Roupala brasiliensis e Cedrela fissilis) da Floresta com Araucária. Nossa hipótese é que a simetria foliar, associada a outros atributos foliares, minimiza o autosombreamento. Foram mensurados o índice de assimetria, o comprimento do pecíolo, a área foliar total, ângulo foliar, o comprimento do internó e o diâmetro do caule. O índice de assimetria não indicou uma distinção clara entre folhas assimétricas e simétricas. Folhas classificadas como assimétricas apresentaram maior índice na região mediana e basal da folha, enquanto as folhas simétricas apresentaram maior índice na região apical. Os resultados também indicaram um ajuste entre os atributos estruturais que permitiram um arranjo tridimensional das folhas vantajoso para a captura de luz, o que parece ser uma resposta à pressão seletiva pelas condições heterogêneas de luz do sub-bosque de floresta ombrófila.

Asunto(s)

Forma del Núcleo Celular , Taiga , Árboles/anatomía & histología , Árboles/citología , Árboles/química

RESUMEN

The aim of this work was to evaluate the effect of quebracho tannins extract (QTE) on feed intake, dry matter (DM) digestibility, and methane (CH4) emissions in cattle fed low-quality Pennisetum purpureum grass. Five heifers (Bos taurus × Bos indicus) with an average live weight (LW) of 295 ± 19 kg were allotted to five treatments (0, 1, 2, 3, and 4% QTE/kg DM) in a 5 × 5 Latin square design. Intake, digestibility, and total methane emissions (L/day) were recorded for periods of 23 h when cattle were housed in open-circuit respiration chambers. Dry matter intake (DMI), organic matter intake (OMI), dry matter digestibility (DMD), and organic matter digestibility (OMD) were different between treatments with 0 and 4% of QTE/kg DM (P < 0.05). Total volatile fatty acid and the molar proportion of acetate in the rumen was not affected (P < 0.05); however, the molar proportion of propionate increased linearly (P < 0.01) for treatments with 3 and 4% QTE. Total CH4 production decreased linearly (P < 0.01) as QTE increased in the diet, particularly with 3 and 4% concentration. When expressed as DMI and OMI by CH4, production (L/kg) was different between treatments with 0 vs 3 and 4% QTE (P < 0.05). It is concluded that the addition of QTE at 2 or 3% of dry matter ration can decrease methane production up to 29 and 41%, respectively, without significantly compromising feed intake and nutrients digestibility.

Asunto(s)

Anacardiaceae/química , Dieta/veterinaria , Digestión/efectos de los fármacos , Conducta Alimentaria/efectos de los fármacos , Metano/metabolismo , Taninos/administración & dosificación , Contaminantes Atmosféricos/metabolismo , Alimentación Animal/análisis , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Bovinos , Suplementos Dietéticos/análisis , Relación Dosis-Respuesta a Droga , Femenino , Pennisetum/fisiología , Extractos Vegetales/administración & dosificación , Árboles/química

RESUMEN

Shade plants of ombrophilous forests are subjected to light-limiting conditions and need toinvest in architectural structures associated with leaf symmetry to increase light capture. This study investigated the leaf architecture of six Araucaria forest tree species with distinct symmetry: Cupania vernalis, Casearia sylvestris, Schinus terebinthifolius, Piper gaudichaudianum, Roupala brasiliensis and Cedrela fissilis. We hypothesized that symmetry, associated with other traits, minimizes self-shading. Asymmetry index, petiole length, total leaf area, leaf angle, internode length and stem diameter were measured. The asymmetry index did not indicate a clear distinction between asymmetric and symmetric leaves. Leaves classified as asymmetric had higher values for the asymmetry index in the median and basal regions of the leaf, while symmetrical leaves had higher values in the apical region. The results also indicated an adjustment among structural leaf traits that facilitated a three-dimensional organization that produced an advantageous arrangement for light capture, which seems to be a response to selective pressure by the heterogeneous light conditions of the ombrophilous forest understory.(AU)

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Nas florestas ombrófilas, as plantas de sombra estão sujeitas a condições limitantes de luz enecessitam investir em atributos estruturais associados à simetria foliar para maximizar a captura da luz. Esse estudo investigou a arquitetura foliar de seis espécies arbóreas (Cupania vernalis, Casearia sylvestris, Schinus terebinthifolius, Piper gaudichaudianum, Roupala brasiliensis e Cedrela fissilis) da Floresta com Araucária. Nossa hipótese é que a simetria foliar, associada a outros atributos foliares, minimiza o autosombreamento. Foram mensurados o índice de assimetria, o comprimento do pecíolo, a área foliar total, ângulo foliar, o comprimento do internó e o diâmetro do caule. O índice de assimetria não indicou uma distinção clara entre folhas assimétricas e simétricas. Folhas classificadas como assimétricas apresentaram maior índice na região mediana e basal da folha, enquanto as folhas simétricas apresentaram maior índice na região apical. Os resultados também indicaram um ajuste entre os atributos estruturais que permitiram um arranjo tridimensional das folhas vantajoso para a captura de luz, o que parece ser uma resposta à pressão seletiva pelas condições heterogêneas de luz do sub-bosque de floresta ombrófila.(AU)

Asunto(s)

Taiga , Forma del Núcleo Celular , Árboles/anatomía & histología , Árboles/química , Árboles/citología