Comparison of powdered and fresh jambu (Acmella oleracea).

Jambu, Acmella oleracea (L.), is a low-growing herb plant, with cylindrical, fleshy, decumbent and branched stem varying from 20 to 30 cm in height. It is an abundantly cultivated and consumed vegetable in the northern region of Brazil and usually consumed in preparations of typical foods of the Amazon region. So, this work aimed to compare the chemical composition and physical chemistry of powdered and jambu leaf mass. Acmella oleracea plants were selected, sanitized and their leaves were crushed (without adding water). The mass was dried in an oven with forced air circulation under different conditions of temperature (60, 70 and 80 °C) and relative humidity (13.09, 8.14 and 5.45%, respectively), in two layer thicknesses (0.5 and 1.0 cm). The physical, chemical, physicochemical parameters moisture content, water activity, ash, protein, lipids, pH, total titratable acidity and color were analyzed in powdered and fresh leaves. Contrast test was used to evaluate the interaction between the layer thicknesses at 5% level of significance. Considering the contrasts, the parameters total soluble solids, ash, protein and lipids do not differ from those in the fresh sample, demonstrating that these parameters are not modified or degraded with the drying conditions. The pH and color parameters differed from those of the fresh material, due to degradation, which can be linked to the rise in temperature sensitivity. The moisture content and water activity also differed and were reduced, contributing to conservation of the material. Contrast analysis made it possible to conclude that the physicochemical composition did not undergo modifications through the use of drying. In addition, a powdered material with reduced water activity was obtained.

Effect of overexpression of citrus 9-cis-epoxycarotenoid dioxygenase 3 (CsNCED3) on the physiological response to drought stress in transgenic tobacco.

9-cis-epoxycarotenoid dioxygenase (NCED) encodes a key enzyme in abscisic acid (ABA) biosynthesis. Little is known regarding the regulation of stress response by NCEDs at physiological levels. In the present study, we generated transgenic tobacco overexpressing an NCED3 ortholog from citrus (CsNCED3) and investigated its relevance in the regulation of drought stress tolerance. Wild-type (WT) and transgenic plants were grown under greenhouse conditions and subjected to drought stress for 10 days. Leaf predawn water potential (Ψwleaf), stomatal conductance (gs), net photosynthetic rate (A), transpiration rate (E), instantaneous (A/E) and intrinsic (A/gs) water use efficiency (WUE), and in situ hydrogen peroxide (H2O2) and abscisic acid (ABA) production were determined in leaves of irrigated and drought-stressed plants. The Ψwleaf decreased throughout the drought stress period in both WT and transgenic plants, but was restored after re-watering. No significant differences were observed in gs between WT and transgenic plants under normal conditions. However, the transgenic plants showed a decreased (P ≤ 0.01) gs on the 4th day of drought stress, which remained lower (P ≤ 0.001) than the WT until the end of the drought stress. The A and E levels in the transgenic plants were similar to those in WT; therefore, they exhibited increased A/gs under drought conditions. No significant differences in A, E, and gs values were observed between the WT and transgenic plants after re-watering. The transgenic plants had lower H2O2 and higher ABA than the WT under drought conditions. Our results support the involvement of CsNCED3 in drought avoidance.

Bacterial cellulose membranes as drug delivery systems: an in vivo skin compatibility study.

Bacterial cellulose (BC) is a highly pure form of cellulose, produced in the form of a swollen membrane by several bacteria that demonstrated to be able to modulate the skin release of model drugs. In the present study, the skin irritation potential of BC was evaluated in human subjects. BC membranes with and without glycerin (acting as plasticizer) were tested. No significant differences were observed for transepidermal water loss (TEWL) measurements in comparison with negative control, 2 and 24 h after patch removal, which is an indicator of an absence of barrier disruption. Similar results were found for erythema. Clinical scores were zero at both times for all volunteers, with the exception of five volunteers that exhibited weak reactions. BC with glycerin provided a skin moisturizing effect statistically higher than the negative control (p=0.044), which was not observed for BC alone. The good skin tolerance found after a single application under occlusion reinforces the putative interest of BC membranes as supports for drug topical delivery. Besides modifying the mechanical properties, the inclusion of glycerin results in a skin moisturizing effect which could be clinically relevant for the treatment for skin diseases characterized by dryness, such as psoriasis and atopic dermatitis.

Efeitos do sombreamento na anatomia foliar de Gallesia integrifolia (Spreng) Harms e Schinnus terebinthifolius Raddi / Effects of shading on leaf anatomy of Gallesia integrifolia (Spreng) Harms and Schinnus terebinthifolius Raddi

Realizou-se estudo com o objetivo de analisar as alterações na anatomia foliar de Gallesia integrifolia (Spreng) Harms e Schinnus terebinthifolius Raddi quando cultivadas em ambientes de sombra moderada ou densa, simulando as condições naturais encontradas em sistemas agroflorestais tradicionais do sul da Bahia, Brasil. Plantas das duas espécies, com aproximadamente um ano de idade, foram cultivadas em casa de vegetação sob quatro níveis de sombreamento (25%, 17%, 10% e 5%). Estudos anatômicos do limbo foliar foram realizados a partir de material incluído em parafina e seccionado em micrótomo rotativo. Os diferentes níveis de sombreamento ocasionaram alterações na estrutura do mesofilo de ambas as espécies, com diferenças significativas na espessura do parênquima paliçádico, limbo foliar, e densidade estomática. Nas condições em que o experimento foi realizado os resultados obtidos indicaram que G. integrifolia apresenta maior capacidade de aclimatação a ambientes de sombra moderada e densa do que S. terebinthifolius, sendo mais indicada para o cultivo em sistemas agroflorestais pré-estabelecidos.

This study was conducted with the aim of analyzing the changes in the leaf anatomy of Gallesia integrifolia (Spreng) Harms and Schinnus terebinthifolius Raddi when grown in environments with moderate to dense shade, simulating the natural conditions found in traditional agroforestry systems in southern Bahia, Brazil. Plants of both species, being approximately one year-old, were grown at four irradiance levels (25%, 17%, 10% and 5%) in a greenhouse. Leaf anatomical studies were made from material embedded in paraffin and sectioned on a rotary microtome. The different irradiance levels caused a shift in the mesophyll anatomy of both species, with significant differences in palisade parenchyma thickness and leaf stomatal density. In the conditions of this experiment, the results indicated that G. integrifolia has a higher capacity for acclimatization to moderate to dense shade than S. terebinthifolius, and it is thus more suitable for cultivation in pre-established agroforestry systems.

Changes in protein profile detected in seedlings of Caesalpinia peltophoroides (Fabaceae) after exposure to high concentration of cadmium.

Sibipiruna (Caesalpinia peltophoroides Benth) is a tree of the Brazilian Atlantic Forest. It is a flowering ornamental tree widely planted throughout Brazil and indicated for restoration of degraded areas. We examined protein profile changes in leaves of seedlings of C. peltophoroides grown in nutrient solution under greenhouse conditions, after exposure to cadmium (Cd; 32 mg/L). A two-dimensional gel was used to analyze proteins expressed in response to stress 24 and 72 h after initiation of treatment with Cd. Various protein bands were identified that were related to stress response and/or metabolic adjustments, including proteins involved with resistance to stress, including detoxification, degradation, antioxidant, transport, signal transduction, photosynthesis, electron transport, biosynthesis reactions, and transcription regulation. After 24 h of Cd exposure, the genes of most of these proteins were upregulated. These putative proteins were associated with resistance to stress, including heat shock proteins, heat stress transcriptional factor and other transcriptional factors, aquaporins, glutathione transferase and choline monooxygenase. Most of the putative proteins observed after 72 h of exposure to Cd were downregulated. They were mainly photosynthetic process proteins, such as NAD(P)H-quinone oxidoreductase, photosystem I assembly, and photosystem II CP47 chlorophyll apoprotein. There were also proteins involved with degradation, biosynthesis and antioxidant activity, such as ATP-dependent Clp protease, methylthioribose-1-phosphate and glutathione peroxidase 2. Based on preliminary proteomic analysis, we conclude that proteins related to photosynthetic activity are inhibited, decreasing plant performance under stress conditions and that several proteins related to defense mechanisms are activated, inducing the plant defense response.

Leaf carbon assimilation and molecular phylogeny in Cattleya species (Orchidaceae).

We examined leaf CO(2) assimilation and how it varied among species within the orchid genus Cattleya. Measurements of CO(2) assimilation and maximum quantum yield of PS II (Fv/Fm) were made for mature leaves of nine species using a portable system for photosynthesis measurement and a portable fluorometer. Leaf area was measured with an area meter, and the specific leaf mass was determined. DNA of nine Cattleya species and two species of Hadrolaelia was extracted using the CTAB protocol. Each sample was amplified and sequenced using primers for the trnL gene. The phylogenetic analyses, using neighbor-joining and maximum parsimony methods, retrieved a group that included Cattleya and Hadrolaelia species, in which the unifoliate species were separated from the bifoliates. The topologies of the two cladograms showed some similarities. However, C. guttata (bifoliate) was placed in the unifoliate clade in the neighbor-joining tree, while C. warneri (unifoliate) was not placed in this clade in the maximum parsimony tree. Most Cattleya species keep the leaf stomata closed from 6 am to 4 pm. We suggest that C. elongata, C. tigrina and C. tenuis have C(3)-crassulacean acid metabolism since they open their stomata around 12 am. The Fv/Fm values remained relatively constant during the measurements of CO(2) assimilation. The same was observed for the specific leaf mass values, although great variations were found in the leaf area values. When the species were grouped using molecular data in the neighbor-joining analysis, no relation was observed with CO(2) assimilation.