Cd-tolerance markers of Pfaffia glomerata (Spreng.) Pedersen plants: Anatomical and physiological features

Physiological and anatomical features of Cd-tolerance in Pfaffia glomerata were examined by exposing plantlets to nutrient solutions with increasing Cd concentrations (0, 15, 45, and 90 μmol Cd L-1), and possible Cd-tolerance markers were established. Cd contents were found to be higher in roots than in shoots. According to the bio-concentration factor data, this species is effectively a Cd-hyperaccumulator, as previously attested. Cd induced the appearance of xeromorphic characteristics in leaves (decreased water potential, increased numbers and decreased stomata size) and increased root endodermis thickness. The enzymatic antioxidant systems of roots and leaves were differently affected by Cd. The coordinated activities of antioxidant enzymes were effective in reducing Cd-induced reactive oxygen species in plants, mainly in leaves. Root endodermis thickness, stomatal size and numbers, root superoxide dismutase, and guaiacol peroxidase, as well as leaf guaiacol peroxidase and catalase activities can all be considered Cd-tolerance markers in Pfaffia glomerata. Due to its high root Cd accumulation, Pfaffia glomerata may be useful in Cd-phytoextraction programs, however the pharmacological use of plants grown in the presence of Cd must be avoided

Estimativa do IAF de cafeeiro a partir do volume de folhas e arquitetura da planta

The methods used for estimating the leaf area index (LAI) of coffee (Coffea arabica L.) show limitations related to therepresentation of some aspects of coffee crops, affecting the LAI in time and space. This work was developed to propose a method forassessing the LAI of coffee aiming to reduce those limitations. We studied plants in the production phase of the Mundo Novo and Catuaívarieties, in plantations located in Lavras-MG, during the dry season and rainy season from 2010 to 2011. The height, total length ofprimary branches, the length of the region without leaves in the canopy and the LAI of those plants were evaluated. These data wereused to estimate the volume occupied by leaves and, subsequently, to obtain equations that describe the behavior of LAI in relation tothis volume. There were three equations that described the LAI variations in relation to the volume occupied by leaves: linear,expolinear and seasonal. These three models showed realistic estimates when applied to plants from plantations located in TrêsPontas-MG. Potentially, this method can be applied for estimating the LAI of a plant or canopies. It has the advantage of a morerealistic representation of the shape of the plant in time and space compared to similar methods. With the proposed method is expectedto meet the demands of productivity forecasting models for coffee, reducing the limitations observed in the commonly used methods forLAI determination.Os métodos de estimativa do índice de área foliar (IAF) utilizados para cafeeiros (Coffea arabica L.) apresentamlimitações relacionadas à representação de particularidades da cultura que afetam o IAF no tempo e no espaço. Desenvolveuseeste trabalho objetivando propor um método de estimativa do IAF de forma a reduzir essas limitações. Foram utilizadoscafeeiros em fase produtiva, de cultivos da região de Lavras-MG, das variedades Mundo Novo e Catuaí, coletados durantea estação seca e a estação chuvosa de 2010 a 2011. Nessas plantas avaliou-se a altura a partir do nível do solo, comprimentototal de ramos plagiotrópicos, o comprimento da região sem folhas na copa e o IAF. Esses dados foram utilizados paraestimar o volume de folhas das plantas e, posteriormente, para a obtenção de equações que descrevem o comportamento doIAF em função do volume de folhas. Verificaram-se três ajustes das variações de IAF em função do volume de folhas:comportamento linear, expolinear e sazonal. Os três modelos apresentaram estimativas realistas, quando aplicados emcafeeiros do município de Três Pontas-MG. Potencialmente, os modelos podem ser aplicados na estimativa do IAF de umaplanta isolada ou para parcelas homogêneas. Possuem a vantagem de uma representação mais realista da forma da planta notempo e no espaço em comparação com métodos semelhantes. Com o método proposto, espera-se atender demandas demodelos de previsão de produtividade de cafeeiros, reduzindo as limitações observadas nos métodos comumente utilizadospara a determinação do IAF

Highly reactive light-dependent monoterpenes in the Amazon

Despite orders of magnitude difference in atmospheric reactivity and great diversity in biological functioning, little is known about monoterpene speciation in tropical forests. Here we report vertically resolved ambient air mixing ratios for 12 monoterpenes in a central Amazon rainforest including observations of the highly reactive cis-β-ocimene (160 ppt), trans-β-ocimene (79 ppt), and terpinolene (32 ppt) which accounted for an estimated 21% of total monoterpene composition yet 55% of the upper canopy monoterpene ozonolysis rate. All 12 monoterpenes showed a mixing ratio peak in the upper canopy, with three demonstrating subcanopy peaks in 7 of 11 profiles. Leaf level emissions of highly reactive monoterpenes accounted for up to 1.9% of photosynthesis confirming light-dependent emissions across several Amazon tree genera. These results suggest that highly reactive monoterpenes play important antioxidant roles during photosynthesis in plants and serve as near-canopy sources of secondary organic aerosol precursors through atmospheric photooxidation via ozonolysis. © 2015. The Authors

Diel and seasonal changes of biogenic volatile organic compounds within and above an Amazonian rainforest

The Amazonian rainforest is a large tropical ecosystem, which is one of the last pristine continental terrains. This ecosystem is ideally located for the study of diel and seasonal behaviour of biogenic volatile organic compounds (BVOCs) in the absence of local human interference. In this study, we report the first atmospheric BVOC measurements at the Amazonian Tall Tower Observatory (ATTO) site, located in central Amazonia. A quadrupole proton-transfer-reaction mass spectrometer (PTR-MS), with seven ambient air inlets, positioned from near ground to about 80 m (0.05, 0.5, 4, 24, 38, 53 and 79 m above the forest floor), was deployed for BVOC monitoring. We report diel and seasonal (February-March 2013 as wet season and September 2013 as dry season) ambient mixing ratios for isoprene, monoterpenes, isoprene oxidation products, acetaldehyde, acetone, methyl ethyl ketone (MEK), methanol and acetonitrile. Clear diel and seasonal patterns were observed for all compounds. In general, lower mixing ratios were observed during night, while maximum mixing ratios were observed during the wet season (February-March 2013), with the peak in solar irradiation at 12:00 LT (local time) and during the dry season (September 2013) with the peak in temperature at 16:00 LT. Isoprene and monoterpene mixing ratios were the highest within the canopy with a median of 7.6 and 1 ppb, respectively (interquartile range (IQR) of 6.1 and 0.38 ppb) during the dry season (at 24 m, from 12:00 to 15:00 LT). The increased contribution of oxygenated volatile organic compounds (OVOCs) above the canopy indicated a transition from dominating forest emissions during the wet season (when mixing ratios were higher than within the canopy), to a blend of biogenic emission, photochemical production and advection during the dry season when mixing ratios were higher above the canopy. Our observations suggest strong seasonal interactions between environmental (insolation, temperature) and biological (phenology) drivers of leaf BVOC emissions and atmospheric chemistry. Considerable differences in the magnitude of BVOC mixing ratios, as compared to other reports of Amazonian BVOC, demonstrate the need for long-term observations at different sites and more standardized measurement procedures, in order to better characterize the natural exchange of BVOCs between the Amazonian rainforest and the atmosphere. © Author(s) 2015

A estratificação e o manejo adequado da dor: Stratification and proper pain management

A dor é um potencial de risco para a saúde pública, esta se caracteriza pela experiência multidimensional associada a aspectos físicos e emocionais. A dor alerta o perigo e evita danos orgânicos, mas quando está impossibilita atividades diárias e impacta a qualidade de vida do paciente é classificada como patológica e urge por interferência médica. O seguinte artigo objetivou descrever através da revisão narrativa de literatura os aspectos referentes da dor e o seu manejo adequado. A dor é um amplo complexo que possui a classificação conforme a localização, tipo, intensidade, periodicidade. As categorias referentes a dor são nociceptivas, neuropática, psicogênica. Ademais, as síndromes dolorosas são diversas e podem acometer qualquer sistema do corpo. Ressaltando ser essencial a categorização do máximo possível de informações para conduzir adequadamente ao tratamento destas enfermidades.&nbsp

Highly reactive light‐dependent monoterpenes in the Amazon

Despite orders of magnitude difference in atmospheric reactivity and great diversity in biological functioning, little is known about monoterpene speciation in tropical forests. Here we report vertically resolved ambient air mixing ratios for 12 monoterpenes in a central Amazon rainforest including observations of the highly reactive cis-β-ocimene (160 ppt), trans-β-ocimene (79 ppt), and terpinolene (32 ppt) which accounted for an estimated 21% of total monoterpene composition yet 55% of the upper canopy monoterpene ozonolysis rate. All 12 monoterpenes showed a mixing ratio peak in the upper canopy, with three demonstrating subcanopy peaks in 7 of 11 profiles. Leaf level emissions of highly reactive monoterpenes accounted for up to 1.9% of photosynthesis confirming light-dependent emissions across several Amazon tree genera. These results suggest that highly reactive monoterpenes play important antioxidant roles during photosynthesis in plants and serve as near-canopy sources of secondary organic aerosol precursors through atmospheric photooxidation via ozonolysis. © 2015. The Authors

Cd-tolerance markers of Pfaffia glomerata (Spreng.) Pedersen plants: anatomical and physiological features

Physiological and anatomical features of Cd-tolerance in Pfaffia glomerata were examined by exposing plantlets to nutrient solutions with increasing Cd concentrations (0, 15, 45, and 90 μmol Cd L-1), and possible Cd-tolerance markers were established. Cd contents were found to be higher in roots than in shoots. According to the bio-concentration factor data, this species is effectively a Cd-hyperaccumulator, as previously attested. Cd induced the appearance of xeromorphic characteristics in leaves (decreased water potential, increased numbers and decreased stomata size) and increased root endodermis thickness. The enzymatic antioxidant systems of roots and leaves were differently affected by Cd. The coordinated activities of antioxidant enzymes were effective in reducing Cd-induced reactive oxygen species in plants, mainly in leaves. Root endodermis thickness, stomatal size and numbers, root superoxide dismutase, and guaiacol peroxidase, as well as leaf guaiacol peroxidase and catalase activities can all be considered Cd-tolerance markers in Pfaffia glomerata. Due to its high root Cd accumulation, Pfaffia glomerata may be useful in Cd-phytoextraction programs, however the pharmacological use of plants grown in the presence of Cd must be avoided

Plant physiological ecology and the global changes Ecofisiologia vegetal e as mudanças globais

The global changes are marked by alteration on the normal patterns of important biochemical and biophysical processes of the Earth. However, the real effects as well as the feedbacks of the global changes over vegetation are still unclear. Part of this uncertainty can be attributed to the inattention of stakeholders and scientists towards vegetation and its complex interrelations with the environment, which drive plant physiological processes in different space-time scales. Notwithstanding, some key subjects of the global changes could be better elucidated with a more plant physiological ecology approach. We discuss some issues related to this topic, going through some limitations of approaching vegetation as a static component of the biosphere as the other sub-systems of the Earth-system change. With this perspective, this review is an initial reflection towards the assessment of the role and place of vegetation structure and function in the global changes context. We reviewed the Earth-system and global changes terminology; attempted to illustrate key plant physiological ecology researches themes in the global changes context; consider approaching plants as complex systems in order to adequately quantify systems characteristics as sensibility, homeostasis, and vulnerability. Moreover, we propose insights that would allow vegetation studies and scaling procedures in the context of the Earth-system. We hope this review will assist researchers on their strategy to identify, understand and anticipate the potential effects of global changes over the most vulnerable vegetation processes from the leaf to the global levels.<br>As mudanças globais englobam importantes alterações nos padrões normais de processos bioquímicos e biofísicos da Terra. Os reais efeitos e retroalimentações das mudanças globais sobre a vegetação ainda são incertos. Parte das incertezas pode ser atribuída à falta de atenção de cientistas e políticos para a vegetação, enquanto componente do sistema terrestre. Entretanto, algumas questões sobre as mudanças globais poderiam ser mais bem esclarecidas por abordagens mais voltadas à ecofisiologia vegetal. Nesse artigo, alguns pontos relacionados e esses problemas, como as limitações em se abordar a vegetação como um componente estático da atmosfera enquanto outros subsistemas do sistema terrestre são dinâmicos, são discutidos. Dentro dessa perspectiva, essa revisão traz uma reflexão inicial do papel da vegetação, em termos de estrutura e funcionamento, no contexto das mudanças globais. Para isso, foi feita uma revisão das terminologias relacionadas às mudanças globais e ao sistema terrestre, buscou-se ilustrar alguns dos principais temas de pesquisa da ecofisiologia vegetal no contexto das mudanças globais. Foram feitas considerações em relação ao tratamento de plantas como sistemas complexos, o que é importante para o estudo de aspectos relacionados à sensibilidade, estabilidade e vulnerabilidade a variações ambientais. Finalmente, são discutidas alternativas que podem ser utilizadas para incorporar aspectos do funcionamento da vegetação, de forma dinâmica, em estudos de mudanças globais, considerando o desafio de mudança de escalas. Espera-se que essa revisão possa auxiliar pesquisadores subsidiando suas estratégias de identificação e compreensão dos efeitos potenciais das mudanças globais sobre os processos mais vulneráveis da vegetação, da folha ao globo