Aspidosperma Tomentosum Research Articles

The type of substrate does not influence the intraspecific population structure of shrub‐tree species in the Brazilian savanna

AbstractLocal environmental conditions influence the occurrence and abundance of populations, and therefore, the contribution of the same species to the ecological structure and processes of communities can vary in different environments. We investigated the influence of the substrate on the intraspecific population structure of four shrub‐tree species from the Brazilian savanna (Aspidosperma tomentosum, Byrsonima pachyphylla, Davilla elliptica, and Ouratea hexasperma) that occur in adjacent areas, but under different environmental conditions: in shallow soils with rocky outcrops and steep relief in Rupestrian Savanna, and in deep soils and flat relief in Typical savanna. We hypothesized that the relief and physical–chemical conditions of the soil in the Rupestrian Savanna limit the establishment and development of species regarding the abundance of individuals and the horizontal and vertical structure of populations. We found that in the Rupestrian Savanna, the soil has higher levels of total cation exchange capacity and phosphorus, while in Typical Savanna, it is associated with higher pH, base saturation, and clay levels. We show that intraspecific variations do not differ between the two environments in number of individuals, average values of trunk diameter, and total plant height. We observed that the same species contributes in different ways to the structuring of communities in both environments. Our hypothesis was rejected because the population structure was not molded by the substrate type. We conclude that the shrub‐tree species seem to find adaptive alternatives to colonize the different types of substrates, for example, establishing in less stressful microhabitats on the rocky environments.

Climate-growth relationships for Aspidosperma tomentosum Mart. in South American tropical dry forests

The precise demarcation and cross-dating of tree rings in Aspidosperma tomentosum Mart., a valuable timber species in the tropical dry forests of South America, were used to develop the first well-replicated chronology covering the period 1843–2015. A. tomentosum Mart. tree growth is strongly regulated by soil water availability prior to and during the current growing season. In the context of increased drought severity due to climate change, determining of climate influences on A. tomentosum Mart. radial growth is necessary to establish appropriate guidelines for the management, conservation and restoration of this species, currently affected by extreme weather events, extensive fires and deforestation in the Chiquitania forests, Bolivia. Tropical forest ecosystems play a critical role in the functioning of the Earth; thus, a better understanding of the influences of climate on tree growth is needed to estimate changes in forest productivity and consequently in carbon sink variations at regional and global scales. In the context of global environmental changes, our study aimed at using the growth rings of A. tomentosum Mart. to establish the relationships between radial growth and climatic variations. The anatomical characterization of the wood elements facilitated the precise annual band delimitation and the rejection of samples with false rings and growth anomalies. A tree-ring chronology was developed using traditional dendrochronological methods and the relationships with climate determined using correlation functions. The chronology is based on 20 individuals and covers the period 1843–2015. Tree-ring statistics indicate an important common signal in growth variations between trees (R-bar = 0.31, EPS = 0.90). Interannual variations in A. tomentosum Mart. are directly related to total annual precipitation (r = 0.76) and inversely to mean annual temperature (r = − 0.44). These relationships are similar to those documented for other commercial species (Centrolobium microchaete, Schinopsis brasiliensis) from tropical dry forests in South America, suggesting a consistent climatic influence on tree growth at a regional scale. The strong dependence of tree growth on climate variability is a major concern, as climate change scenarios for tropical dry forests in South America predict an increase in the frequency and intensity of droughts, which in turn would reduce the A. tomentosum Mart. growth during the twenty-first century.

Photochemical performance and source-sink relationships in galls induced by Pseudophacopteron longicaudatum (Hemiptera) on leaves of Aspidosperma tomentosum (Apocynaceae)

The establishment of the galling insect generates a biotic stress that leads to tissue transformation. However, galls can maintain chlorophyll (Chl) and consequently photosynthesize. Herein, we evaluated the consequences of the biotic stress generated by the galling insect Pseudophacopteron longicaudatum on photosynthetic rate during the leaf galls development on Aspidosperma tomentosum. In addition, we quantified polysaccharides and water content in order to evaluate the capacity of gall tissues to drain photoassimilates. The non-galled leaves contained more Chl and carotenoids per gram of fresh mass. Galls had lower values of maximum PSII quantum yield, fluorescence decline ratio, and nonphotochemical quenching compared to non-galled tissue. These results showed a significant reduction of photosynthesis photochemistry in galled tissues although total soluble sugar did not differ between gall and non-galled leaves. Water-soluble polysaccharides, relative water content, and leaf specific mass were significantly higher in galls and increased through their development, suggesting a sink relationship.

Environmental variables drive phenological events of anemocoric plants and enhance diaspore dispersal potential: A new wind-based approach

Phenological studies of Brazilian savanna vegetation have described a generalized phenological pattern for all species, mainly based on rainfall and temperature. Few studies have considered wind as an explanatory factor; abiotic factors may impact differently on phenophases, and one phenophase may influence the performance of another. Thus, we aim to describe the phenological patterns of five anemocoric plant species (Aspidosperma tomentosum, Dalbergia miscolobium, Kielmeyera coriacea, Peixotoa tomentosa and Qualea multiflora) in the face of different climatic conditions, mainly evaluating the effects of wind on the ripe diaspore. We addressed three main questions: (1) What is the phenological behavior of each of these five anemocoric species in a seasonal environment? (2) Which climatic variables best explain each phenophase? (3) Does the dispersal of ripe diaspores peak shortly after deciduousness? We found that (i) our focal species showed similar phenological patterns, except for the floral bud and flower phenophases of two species (A. tomentosum and P. tomentosa), and the young fruit phase; (ii) each abiotic variable has a specific level of influence for each phenophase, but the most important variables were rainfall and wind speed; and (iii) the dispersal peak of ripe diaspores occurred shortly after deciduousness, and when plants had fewer leaves. We conclude that the phenological patterns of these five anemocoric plants are similar, but that the patterns observed are not necessarily those described for Cerrado species. Additionally, we found that wind is an important factor in the expression of specific phenophases, and that the performance of some phenological events can be influenced by others, especially diaspore dispersal.

Pseudophacopteron longicaudatum (Hemiptera) induces intralaminar leaf galls on Aspidosperma tomentosum (Apocynaceae): a qualitative and quantitative structural overview.

The structural complexity of galls depends on species-specific interaction driven by the galling taxa. However, the host plant and environment stressors can impose limits on gall developmental patterns and impact the establishment of gall morphology. Herein, we employed qualitative and quantitative approaches in order to elucidate how cell divisions, elongation patterns, and tissue organization are determinant for the development of intralaminar gall morphology induced by Pseudophacopteron longicaudatum Malenovský, Burckhardt, Queiroz, Isaias & Oliveira (Hemiptera: Psylloidea: Phacopteronidae) on leaves of Aspidosperma tomentosum Mart. (Apocynaceae). In addition, we aimed to determine which anatomical process can discriminate the stages of gall development, plus, examine the histochemical and cytological profiles of the galls. The differentiated structures, mainly abaxial epidermis and spongy parenchyma, are associated with gall closure, with hyperplastic events concentrated in the young phase of the galls. Thus, epidermis and spongy parenchyma hypertrophy and are responsible for the determination of the nymphal chamber formation and gall shape. The mature galls do not differentiate into a typical nutritive cells and do not develop a histochemical gradient in their tissues. The cytological features of galls such as plastoglobules and multivesicular bodies are related to ROS scavenging mechanisms due the high oxidative stress.

Galling insects as phenotype manipulators of cell wall composition during the development of galls induced on leaves of Aspidosperma tomentosum (Apocynaceae)

The gall structure is built from redifferentiation of host plant tissues, changing the cell wall proprieties and associated functions. Because of the oxidative stress imposed by the galling insect on the plant tissues, some phenotypic traits associated with cell wall metabolism may be suppressed during gall development. Using an immunocytochemical approach we investigated the pectin and glycoprotein composition of the cell walls during non-galled leaf development and galls induced on Aspidosperma tomentosum (Apocynaceae). Embedding in historesin was used for anatomical characterization, as well as for immunocytochemical analyses. The samples were probed with the primary monoclonal antibodies JIM5, JIM7, LM1, LM2, LM5 and LM6. The gall develops especially from cell hypertrophy and hyperplasia of the spongy and palisade parenchyma, which determine its shape. Epitopes of β-D-galactan and α-L-arabinan in the galls were totally suppressed or less expressed. The increased labeling of homogalacturonan epitopes, especially in senescent galls, is a clear indicator that pectin methylesterase activity is maintained despite oxidative stresses imposed by the galling insect. Arabinogalactan proteins were not detected in any non-galled leaf or gall stages. The galling insect deeply changed the structure and deposition pattern of the cell wall, promoting new functionalities in the gall tissue compartments.

In vitro antileishmanial activity of leaf and stem extracts of seven Brazilian plant species

Ethnopharmacological relevanceLeishmaniasis is a parasitic disease that affects people all over the world. The number of cases of leishmaniasis is increasing and the drugs used for its treatment are toxic and not always effective. The recognition of the global nature of this disease and its direct or indirect effects on health economics and actions focuses attention on the development of new therapeutic options. In Brazil, this parasitic disease is endemic in many regions. The plants used by the population against leishmaniasis can be good starting points in the search of new lead compounds for antileishmanial drugs. Aim of the studyThe aim of the present study was to investigate the antileishmanial activity of extracts from leaves and stems of seven Brazilian plant species used by the population to treat leishmaniasis, and symptoms that might be related to Leishmania infections. Materials and methodsTwenty two extracts from seven plants belonging to five different botanical families were prepared by different methods and evaluated for their effect on the viability of promastigote forms of Leishmania infantum (MHOM/BR/1967/BH46) using the resazurin-based colorimetric assay. The extracts were considered active when they inhibited the growth of promastigotes in a percentage greater than or equal to 50% at 100 and 200 µg/mL. The active samples were further investigated to determine IC50, CC50 and SI values against promastigote forms of L. infantum. The active and non-cytotoxic extracts (SI> 10) were evaluated against amastigote forms of L. infantum. In addition, the active extracts against the amastigote forms were analyzed by TLC and HPLC, while the EtOAc extract of stems from Aspidosperma tomentosum was also evaluated by GC/MS. ResultsAmong the twenty two extracts evaluated, two were considered active against L. infantum. The EtOH extract of leaves from Dyospiros hispida (IC50 55.48 ± 2.77 µg/mL and IC50 80.63 ± 13.17 µg/mL, respectively) and the EtOAc extract of stems from Aspidosperma tomentosum (IC50 9.70 ± 2.82 µg/mL and IC50 15.88 ± 1.53 µg/mL, respectively) inhibited significantly the growth of promastigote and amastigote forms of L. infantum. Some extracts, although active in the initial screening, were considered toxic since the SI was lower than 10. In TLC and HPLC analysis the leaf extract of Dyospiros hispida showed the presence of anthraquinones, terpenes and saponins, and in the EtOAc extract of stems from Aspidosperma tomentosum alkaloids and flavonoids were detected. In addition, in the latter extract the indole alkaloids uleine and dasycarpidone could be identified by GC/MS. ConclusionsThe ethnopharmacological data of Aspidosperma tomentosum and Dyospiros hispida in part support the results found in the biological models used. Extracts of Aspidosperma tomentosum and Dyospiros hispida presented promising results against L. infantum.

Antihypertensive and Vasorelaxant effects of the ethanolic extract from the stem bark of Aspidosperma tomentosum Mart

Aspidosperma species have been traditionally used for the treatment of cardiovascular disease. These species are important sources of indole alkaloids, which are responsible for different cardiovascular effects. Based on this premise, and as there are still no studies related to the cardiovascular effects of the ethanolic extract from the stem bark of Aspidosperma tomentosum (EEAT). The aim of the present study was to evaluate the possible mechanism of the vasorelaxant action of EEAT in isolated rat mesenteric rings, and to establish its antihypertensive activity. The mean arterial pressure (MAP) and Heart Rate (HR) were measured in hypertensive rats through a catheter inserted in abdominal aorta via femoral artery. The vasodilator effect of EEAT in isolated pre-contracted rat mesenteric rings was examined. The bioactive extract was analyzed via mass spectrometry fingerprinting. EEAT induced relaxation in mesenteric rings pre-contracted with Phe independent of the endothelium. In denuded rings, when incubation with KCl 20 mM or TEA did not change the relaxation. EEAT inhibited the concentration-response curves induced by CaCl2 or Phe and inhibited 80 mM KCl-induced contraction. In pre-contracted preparations with BayK 8644, the EEAT induced relaxation. The transient contraction induced by Phe was inhibited. The oral administration of EEAT reduced MAP and did not alter the HR. Phenolic acids, flavonoids and indole alkaloids were identified in EEAT. In conclusions, the EEAT induced vasorelaxation through a blockade of Ca2+ channels and inhibition of the mobilization of Ca2+ of the IP3-sensivite Ca2+ stores and caused an antihypertensive effect.

Levantamento etnobotânico de plantas utilizadas como anti-hiperlipidêmicas e anorexígenas pela população de Nova Xavantina-MT, Brasil

O presente trabalho verificou a utilização de plantas medicinais encontradas no Cerrado mato-grossense para o tratamento de hiperlipidemias e obesidade. Entrevistas com 180 pessoas acima de 50 anos foram realizadas em Nova Xavantina-MT. O questionário abordou nome popular, parte utilizada, forma de preparo e uso das espécies citadas, além de informações gerais sobre o uso de plantas. As dez plantas mais citadas foram coletadas, identificadas e estudadas por meio de uma revisão bibliográfica. A maioria dos entrevistados (95,6%) declarou utilizar plantas medicinais regularmente, sendo que 71,5% deles herdaram o conhecimento sobre plantas dos pais e avós e 94,20% relataram aconselhar o uso aos mais jovens. Além disso, 93,6% atestaram que as plantas são mais eficazes que os medicamentos de farmácia e 57% consideraram forte o efeito das mesmas, ou seja, sempre resolvem o problema de saúde. Quanto aos efeitos adversos, 95,9% disseram nunca ter sentido após o uso de plantas. Dos entrevistados, 56,7% conheciam ou já haviam utilizado plantas medicinais no tratamento de hiperlipidemias e obesidade, sendo citadas 54 espécies medicinais diferentes pertencentes a 53 gêneros e 38 famílias, com destaque para Fabaceae (13%). As dez plantas mais citadas foram: guatambu (Aspidosperma tomentosum Mart.), quina-do-cerrado (Strychnos pseudoquina St. Hil.), ipê-roxo [Tabebuia impetiginosa (Mart. Ex DC.) Standl], embaúba (Cecropia pachystachya Trec.), calunga (Simaba sp.), pata-de-vaca [Bauhinia rufa (Bong.) Steud.], mangaba (Hancornia speciosa Gomez), batata-de-tiú [Jatropha elliptica (Pohl.) Muell. Arg.], folha-de-carne (Casearia sylvestris Sw.) e manacá (Spiranthera odoratissima A. St.-Hil.). A folha foi a parte mais utilizada (46%) e o preparo das plantas ocorre principalmente por meio de infusão citado por 36,5% dos entrevistados. Apesar do uso popular destas plantas no combate as hiperlipidemias e obesidade, há necessidade de estudos fitoquímicos e farmacológicos que comprovem estas atividades, com vistas ao desenvolvimento de um fitoterápico.

Fitossociologia e diversidade florística em área de cerrado sob vários níveis de antropização, Rio Pardo de Minas, MG

Este estudo teve como objetivo avaliar a diversidade e a similaridade florística de ambientes de Cerrado, sob diferentes níveis de antropização por uso agrícola e extrativismo, e gerar base de dados para subsidiar propostas de desenvolvimento sustentável para a região Norte de Minas e sistemas de agricultura tradicional. Foram amostradas 4 áreas nos seguintes ambientes: Areião, Areiãozinho, Chapada de Latossolo e Tabuleiro, cujas identificações foram feitas a partir de informantes-chave na Comunidade Água Boa, em Rio Pardo de Minas (MG). As unidades amostrais foram distribuídas em 8 parcelas de 20 x 50 m, com 5 subparcelas. Foram medidos indivíduos arbóreos com circunferência ao nível do solo maior ou igual a 15 cm. Para análise dos índices fitossociológicos foram calculados os parâmetros densidade, dominância, freqüência, área basal e valor de importância, para cada ambiente. Para a diversidade florística foi calculado o índice de Shannon (H') e para análise da similaridade o índice de Jaccard (Sij). Em todos os ambientes, foi encontrado um total de 477 indivíduos, distribuídos em 21 famílias, com 48 espécies botânicas identificadas e 27 indivíduos não identificados. As cinco famílias mais importantes (maior VI) foram Fabaceae/Papilionoideae, Apocynaceae, Vochysiaceae, Sapotaceae e Fabaceae/Caesalpinoideae. Já as dez espécies de maior importância foram Pouteria ramiflora, Dalbergia miscolobium, Hancornia speciosa, Macherium opacum, Sclerolobium paniculatum var. subvelutinum, Qualea grandiflora, Aspidosperma tomentosum, Byrsonima pachyphylla, Vochysia thyrsoidea e Hymenaea stigonocarpa. O índice H' foi de 3,01; 2,72; 2,48 e 2,09 para Areião, Areiãozinho, Chapada do Latossolo e Tabuleiro, respectivamente. O índice Sij indicou, para todas as combinações entre os ambientes, que existia pouca similaridade florística entre eles.

Antimicrobial evaluation of fungal extracts produced by endophytic strains ofPhomopsissp.

Crude extract of cultures of 13 fungal strains identified as Phomopsis sp. and isolated as endophytes from the leaves of Aspidosperma tomentosum and twigs of Spondias mombin were examined for their antibacterial and antifungal activities. The screening was conducted using the bioautographic TLC agar-overlay technique against bacteria (E. coli, P. aeruginosa, S. aureus), yeast (C. albicans, S. cerevisiae), and readily adapted for use with filamentous fungi (A. niger, F. oxysporum). Three of the 13 extracts effectively inhibited the growth of all test-organisms, indicating that they may represent a potential for pharmaceutical and/or agricultural applications and are worthy of further study.

Caracterização de dois estratos da vegetação em uma área de cerrado no município de Brotas, SP, Brasil

Caracterizaram-se dois estratos da vegetação de uma área de cerca de 300 ha de cerrado stricto sensu, localizada no município de Brotas, SP, quanto à sua estrutura e diversidade, pelo método de parcelas. Para amostragem do estrato arbóreo (diâmetro mínimo de 5 cm, medido a 50 cm acima do nível do solo), foi amostrada área total de 5000 m² (250 x 20 m), divididos em 50 parcelas contíguas de 10 x 10 m (100 m²). Para o estrato inferior (altura < 50 cm e diâmetro do caule inferior a 5 cm), a área total de amostragem foi de 500 m², distribuídos em 50 sub-parcelas de 10 x 1 m (10 m²), demarcadas dentro de cada uma das parcelas maiores. Determinou-se a cobertura do estrato arbóreo pelo método de interceptação de linhas e o índice de agregação das espécies e da comunidade, segundo Payandeh. Foram identificadas, no total, 78 espécies (36 famílias). O estrato arbóreo apresentou densidade de 1150 ind/ha, 7,2 m²/ha de área basal e 19,6 % de cobertura. Foram amostradas, neste estrato, 44 espécies (27 famílias), com H´=3,02 e os indivíduos da comunidade como um todo apresentaram-se agregados (P=4,26). As espécies de maior valor de importância no estrato superior, em ordem decrescente, foram: Acosmium subelegans, Aspidosperma tomentosum, Eriotheca gracilipes, Styrax ferrugineus e Tabebuia ochracea. No estrato inferior, com densidade de 10.220 ind/ha, foram amostradas 61 espécies (32 famílias), destacando-se, em ordem decrescente de densidade relativa: Campomanesia adamantium, Bromelia balansae, Attalea geraensis, Xylopia aromatica e Ocotea pulchella. A comunidade apresentou-se também agregada no estrato inferior (P=3,89) e obteve-se índice de diversidade (H') de 3,32. Algumas espécies abundantes no estrato arbóreo, como Styrax ferrugineus, Eriotheca gracilipes, Piptocarpha rotundifolia e Annona crassiflora, não foram amostradas no estrato inferior, sugerindo a existência de restrições aos processos naturais de reprodução e regeneração. Essas espécies podem estar correndo o risco de extinção local.