Kitchen sponges continue to be heavily used in Brazilian food services, even though they may be very contaminated. The objective of this study was to evaluate the microbiological contamination and the efficacy of two ...Kitchen sponges continue to be heavily used in Brazilian food services, even though they may be very contaminated. The objective of this study was to evaluate the microbiological contamination and the efficacy of two procedures for the disinfection of kitchen sponges used in Brazilian food services. Eighty sponges were collected from food services and then analyzed for the quantification heterotrophic microorganisms (HM), fecal coliforms (CF), Staphylococcus coagulase-positive (SA) microorganisms and to the investigation of the presence of Salmonella sp. (SAM). After that, the sponges were disinfected, separately, by either boiling water for five minutes or immersed in 200ppm sodium hypochlorite, for 10 minutes, added to a rinse with potable water. The results showed that sponges presented HM counts between 3.4 and 10.4 log CFU/sponge, with an average of 9.1 log CFU/sponge, and 76.25% of them presented CF with average counts of 8.4 log CFU/sponge. SA and SAM were found in 2.5% of samples. Both disinfection procedures were able to significantly reduce the bacterial counts, but the boiling method showed a greater reduction (99.9999%) than the method of disinfection by 200 ppm sodium hypochlorite (99.9%). Based on the results it was possible to conclude that kitchen sponges can be very contaminated, but simple disinfection procedure can be applied to significantly reduce the microbial contamination.展开更多
Separately, it is well-documented that phytochromes (phys), gibberellin (GA) and abscisic acid (ABA) strongly control the seed germination in tomato. However, we hipothesized that phys interact with GA or ABA during t...Separately, it is well-documented that phytochromes (phys), gibberellin (GA) and abscisic acid (ABA) strongly control the seed germination in tomato. However, we hipothesized that phys interact with GA or ABA during this response. Thus, we make an analysis of seed germination of ABA deficient (sit), GA constitutive response (pro), phytochrome deficient (au) mutants as well as, specially, au sit and au pro double mutants of tomato?incubated in the dark or light conditions during 120 h [12 h intervals (i)]. Compared to au, which severely?reduced percentage germination (Gi%) and pro, which did not alter Gi%, au pro showed in the light enhanced Gi% and germination speed index (GSI) besides the reduced average germination time (AGT). Moreover, in the dark, germination of au pro was similar to pro. These results indicate that the mechanisms by which GA modulate germination in tomato are light dependent through the phy signaling, whereas intermediary values of Gi%, GSI and AGT in dark and light of au sit compared to au and sit single mutants indicate an additive effect of the au and sit mutations, suggesting that ABA and phy may act through the parallel signaling pathway.展开更多
Above-optimal temperatures reduce yield in many crops, including tomato, largely because of the heat-sensitivity of their reproduction process. A full understanding of heat-stress (HS) response and thermotolerance of ...Above-optimal temperatures reduce yield in many crops, including tomato, largely because of the heat-sensitivity of their reproduction process. A full understanding of heat-stress (HS) response and thermotolerance of tomato reproduction is still lacking. Recently, using external application of the plant <span style="font-family:Verdana;">hormone ethylene, it was demonstrated that ethylene plays a role in</span><span style="font-family:Verdana;"> heat-tolerance of tomato pollen (the male reproductive cells). In order to expand our understanding on involvement of ethylene in tomato pollen thermotolerance, </span><span style="font-family:Verdana;">we analyzed the response of wild type and ethylene-related tomato mutant</span> <span style="font-family:Verdana;">plants to HS, at physiological and molecular levels. We report that mild</span><span style="font-family:Verdana;"> chronic </span><span style="font-family:Verdana;">HS conditions highly reduce the number of viable and germinating pollen </span><span style="font-family:Verdana;">grains as well as the production of seeded fruits in wild type tomato plants, while no significant reduction was detected/observed in pollen quality, number of seeded fruits and seeds per fruit in plants of the ethylene over-producer mutant epinastic. Our findings suggest that ethylene is involved in thermotolerance of tomato reproduction, pointing to an effect on pollen viability and </span><span style="font-family:Verdana;">germination potential, highlighting candidate genes involved in pollen re</span><span style="font-family:Verdana;">sponse to HS (like </span><i><span style="font-family:Verdana;">SlHSP17</span></i><span style="font-family:Verdana;">, </span><i><span style="font-family:Verdana;">SlHSP101</span></i><span style="font-family:Verdana;">, </span><i><span style="font-family:Verdana;">SlMBF1</span></i><span style="font-family:Verdana;">) and suggesting directions for further studies.</span>展开更多
In Diatraea saccharalis larvae, the Malpighian tubules are found along the digestive tube, extending from the middle mesenteric region to the end of the posterior intestine, where they come in contact with the rectum ...In Diatraea saccharalis larvae, the Malpighian tubules are found along the digestive tube, extending from the middle mesenteric region to the end of the posterior intestine, where they come in contact with the rectum to form the cryptonephridium. Scanning and transmission electron microscopy of non-parasitized and parasitized larvae by Cotesia flavipes have indicated that the tubules consist of secretory and reabsorption cells. In parasitized larvae, the occurrence of hemocytes and teratocytes around the tubules is indicative of their role in immunological defense;however, they were not observed in non-parasitized larvae. At day 9 of parasitism, the mitochondria-containing vacuoles and myelin-like figures show signs of degeneration. The results of this study have confirmed that C. flavipes manipulates the physiology and biochemistry of D. saccharalis because the Malpighian tubules of the parasitized larvae remain active until the parasitoid completes its pupal stage and is released from the host organism.展开更多
AIM: To evaluate in bile duct ligated rats whether there were progressive alterations of renal function without changes in histopathology. METHODS: Male Wistar rats were submitted to sham-surgery or bile duct ligation...AIM: To evaluate in bile duct ligated rats whether there were progressive alterations of renal function without changes in histopathology. METHODS: Male Wistar rats were submitted to sham-surgery or bile duct ligation (BDL) and divided according to the post-procedure time (2, 4 and 6-wk). To determine renal function parameters, rats wereplaced in metabolic cages and, at the end of the experiment, blood and urine samples were obtained. Histology and hydroxyproline content were analyzed in liver and renal tissue. RESULTS: Rats with 2 wk of BDL increased free water clearance (P = 0.02), reduced urinary osmolality (P = 0.03) and serum creatinine (P = 0.01) in comparison to the sham group. In contrast, rats at 6 wk of BDL showed features of HRS, including signif icant increase in serum creatinine and reductions in creatinine clearance, water excretion and urinary sodium concentration. Rats with 4 wk of BDL exhibited an intermediate stage of renal dysfunction. Progressive hepatic f ibrosis according to post-procedure time was confirmed by histology. The increased levels of liver hydroxyproline contrasted with the absence of structural changes in the kidney, as assessed by histology and unchanged hydroxyproline content in renal tissue. CONCLUSION: Our data show that BDL produced progressive renal dysfunction without structural changes in the kidney, characterizing HRS. The present model will be useful to understand the pathophysiology of HRS.展开更多
Development of type 2 diabetes has been linked to β-cell failure coupled with insulin resistance and obesity. Adipose tissue, known as the fat store, secretes a number of hormones and proteins collectively termed adi...Development of type 2 diabetes has been linked to β-cell failure coupled with insulin resistance and obesity. Adipose tissue, known as the fat store, secretes a number of hormones and proteins collectively termed adipokines some of which regulate insulin sensitivity. Dysregulation in the secretion of adipokines has been linked to insulin resistance and type 2 diabetes. In this review, we sum-marized evidence of the role of adipokines with focus on leptin, adiponectin, adipsin, visfatin and apelin in the pathogenesis of type 2 diabetes and discussed the potential of saponins to modify the ill-regulated adipokines secretions, which could promote the use of this class of phytochemicals as potential antidiabetics agents.展开更多
Cacao is a crop of global relevance that faces constant demands for improved bean yield.However,little is known about the genomic regions controlling the crop yield and genes involved in cacao bean filling.Hence,to id...Cacao is a crop of global relevance that faces constant demands for improved bean yield.However,little is known about the genomic regions controlling the crop yield and genes involved in cacao bean filling.Hence,to identify the quantitative trait loci(QTL)associated with cacao yield and bean filling,we performed a QTL mapping in a segregating mapping population comprising 459 trees of a cross between‘TSH 1188’and‘CCN 51’.All variables showed considerable phenotypic variation and had moderate to high heritability values.We identified 24 QTLs using a genetic linkage map that contains 3526 single nucleotide polymorphism(SNP)markers.Haplotype analysis at the significant QTL region on chromosome IV pointed to the alleles from the maternal parent,‘TSH 1188’,as the ones that affect the cacao yield components the most.The recombination events identified within these QTL regions allowed us to identify candidate genes that may take part in the different steps of pod growth and bean filling.Such candidate genes seem to play a significant role in the source-to-sink transport of sugars and amino acids,and lipid metabolism,such as fatty acid production.The SNP markers mapped in our study are now being used to select potential highyielding cacao varieties through marker-assisted selection in our existing cacao-breeding experiments.展开更多
This study aimed to observe the viability of the pollen grains of Malpighia emarginata DC. (West Indian cherry) and the action of a lectin in their germination. Lectins are proteins that specifically interact with car...This study aimed to observe the viability of the pollen grains of Malpighia emarginata DC. (West Indian cherry) and the action of a lectin in their germination. Lectins are proteins that specifically interact with carbohydrates, but don’t modify them and bind with high affinity and specificity, promoting a transfer of information that is clearly central to many cellular processes in living beings. For the viability test was used aniline blue in lactophenol. The in vitro germination test used was the hanging drop method, in control medium containing sucrose, boric acid, calcium nitrate and agar. The experiment dealt with three different treatments in order to pollen germination: growing medium without addition of lectin, with 1.0 μg/ml and with 3.0 μg/ml CPL lectin. This lectin is extracted from seeds of Crotalaria pallida L.-Leguminosae. Data on pollen grains were analyzed by one-way ANOVA, with 95% reliability and comparison of averages by Turkey test at 5% probability. It was found that despite previous high viability of the pollen grains (c. 70%), a germinability rate has been low, yet exceptionally larger in pollen samples placed on a growing medium with addition of 3.0 μg/ml of CPL lectin (24%). There was no significant difference among the pollen grains germinate in medium without lectin and those in medium with the addition of only 1.0 μg/ml. According to data obtained in the treatments, CPL lectin, with concentration of 3.0 μg/ml, influenced the formation of the pollen tube and thus more pollen germinated in Malpighia emarginata.展开更多
Cellulases are enzymes responsible for the degradation of cellulose, the major compound in plant cells. Cellulose is a polysaccharide composed of several glucose units linked together by chemical bonds. Cellulases, su...Cellulases are enzymes responsible for the degradation of cellulose, the major compound in plant cells. Cellulose is a polysaccharide composed of several glucose units linked together by chemical bonds. Cellulases, such as endoglucanases, beta-glucosidase and exoglucanases, break the chemical bonds between the glucose units. Fungi, including the endophytic species, can be great cellulase producers. This study aimed to evaluate cellulase production by four endophytic strains of Trichoderma reesei semi-solid media containing sugarcane bagasse, supplemented or not with salts. Two fermentations were carried out for 43 days. Samples were taken every seven days to obtain production peaks. The enzymes were characterized by their optimum pH and temperature of activity and stability upon incubation in the presence of ions, pH and temperature variations. The results showed that the endophytic strains FB1, FB2, FB3 and FB4 of Trichoderma reesei produce cellulases in a sugarcane bagasse medium, supplemented or not with salts, at pH 5.5 and 30°C. The supplemented medium proved to be more appropriate to induce cellulase production after 29 days of fermentation, with FB4 having the best yield: 16.32 ± 2.65 IU/gram of fermented substrate.展开更多
Mayaro virus is an emergent alphavirus that infects humans,leading to Mayaro fever.Approximately fifty percent of infected patients develop arthritis symptoms in the recovery phase,a phase that can last up to a year.T...Mayaro virus is an emergent alphavirus that infects humans,leading to Mayaro fever.Approximately fifty percent of infected patients develop arthritis symptoms in the recovery phase,a phase that can last up to a year.The literature about Mayaro virus infection and its immune response is scarce,which may hamper the development of treatment strategies.We summarize changes in cytokines and chemokines in the acute and recovery phase in Mayaro virus infected patients,and relate this molecular characterization with the immune response.VEGF and IL-12/p70 show pronounced changes in patients in the acute phase,suggesting the development of cellular immunity and Th1 response.IL-6,IL-7,CXCL8/IL-8,IL-13,IL-17,and IFN-γare elevated in patients with arthritis symptoms in the long-term recovery phase,which may be related to the continuous inflammatory process,a possible Th2 inhibiting and promoting Th17 process.Although few studies discuss the issue,with a small number of patients and different backgrounds,inflammatory and immune response and manifestations seem to be closely linked.This information may help to develop the appropriate treatment strategies in Mayaro virus infection.Therefore,we analyzed and summarized data available in literature.展开更多
To establish the chemical profile, and to evaluate the antibacterial and modulatory activity of the ethanolic extracts of the stalk’s inner bark and heartwood of Secondatia floribunda.MethodsQuantification of total p...To establish the chemical profile, and to evaluate the antibacterial and modulatory activity of the ethanolic extracts of the stalk’s inner bark and heartwood of Secondatia floribunda.MethodsQuantification of total phenols and flavonoids was determined by the Folin-Ciocalteu method and aluminum chloride, respectively. Phenolic compounds were identified and quantified by HPLC-DAD (High Performance Liquid Chromatography-Diodearray Detector) and the Infrared Spectroscopy was performed using the measure by Attenuated Total Reflectance with Fourier Transform (ATR-FTIR). Antibacterial assays for determination of the Minimum Inhibitory Concentration (MIC) and modification of aminoglycosides were performed by microdilution.ResultsInfrared spectra showed similar characteristics, having among its main absorption bands hydroxyl group (OH). The antibacterial activity showed clinically significant results for the strains of Staphylococcus aureus and Escherichia coli. In modulation assay, synergic and antagonistic effect for both extracts was observed. Heartwood extract in combination with antibiotics showed a significant MIC reduction at 19.8% (P < 0.000 1)-79.3% (P < 0.01).ConclusionsThis study is the first report of chemical and biological information of Secondatia floribunda suggesting that it is clinically relevant source of a new antibacterial therapy, especially due to the presence of significant levels of phenolic compounds.展开更多
The apple is the second most important fruit in Brazil. However, apple cultivars are susceptible to several diseases that can cause losses after harvesting. Bitter rot is caused by the fungus Colletotrichum gloeospori...The apple is the second most important fruit in Brazil. However, apple cultivars are susceptible to several diseases that can cause losses after harvesting. Bitter rot is caused by the fungus Colletotrichum gloeosporioides and is one of the most damaging summer diseases. The goal of this work was to evaluate the behavior of this fungus in four apple cultivars grown in Brazil (Fuji, Gala, Golden and Green) under two treatments: direct inoculation and isolated fungus. The fungus was isolated by taking fragments from infected fruits, which were stored on Potato Dextrose Agar (PDA) in a laboratory. For the direct treatment, the fungus was removed from infected fruits and directly inoculated into healthy fruits. After inoculation, the fruits were kept at room temperature and the halos of degradation were evaluated every 48 hours. The results demonstrated that direct inoculation was more pathogenic, that the Gala cultivar was the most resistant to the pathogen, and that the Golden cultivar was the most susceptible.展开更多
The SONE oil/water was prepared using the pseudo-ternary phase diagram, using a low energy method with phase inversion by changing the composition. In order to optimize the preparation of SONE, three speeds were used ...The SONE oil/water was prepared using the pseudo-ternary phase diagram, using a low energy method with phase inversion by changing the composition. In order to optimize the preparation of SONE, three speeds were used in the agitator arm and two different rods. The particle size and polydispersity index were determined by Dynamic Light Scattering (DLS) and the stability test by the freeze-thaw cycle. Angiogenesis in chicken embryo egg chorioallantoic membrane and zebrafish (<em>Danio rerio</em>) embryotoxicity was performed. The lower stirring speed and propeller shaft induced smaller particle size (550.2 nm). Regarding angiogenesis, there was a statistically significant difference for all the evaluated parameters (length, caliber, junctions, and number of blood vessel complexes) and the result was higher in SONE when compared to the inhibition control (Dexamethasone), but lower than the induction control (Regederm<span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;"><sup>®</sup></span>) and there was no statistically significant difference between SONE and distilled water. It was observed that the exposure of the zebrafish embryos to SONE caused an increase in the mortality rate dependent on time and concentration. The LC<sub>50</sub> for SONE decreased statistically with increasing exposure (p-value = 0.046). Heart rate decreased significantly with increasing concentration at all exposure times (p-value < 0.05), as a result of progressive embryo mortality. The hatching rate was late until the concentration of 0.0193 mg/mL and no hatching rate was verified from that concentration. Exposure of zebrafish embryos to different concentrations of SONE induced malformations such as spinal changes, pericardial edema and yolk sac edema, but there was no significant difference in the malformation rate of embryos exposed to SONE when compared to the control group. The SONE produced remained stable in the freeze-thaw cycle, with changes only in pH. Despite the low results for embryotoxicity, further studies are needed, aiming at the ideal formulation for angiogenesis purposes.展开更多
Psoriasis is a chronic, recurrent inflammatory cutaneous disease. Psoriasis patients alternate between periods of remission and periods of exacerbation of the disease. Usually, psoriasis severity is clinically evaluat...Psoriasis is a chronic, recurrent inflammatory cutaneous disease. Psoriasis patients alternate between periods of remission and periods of exacerbation of the disease. Usually, psoriasis severity is clinically evaluated using tools like Psoriasis Area and Severity Index that present some limitations and subjectivity. Clinicians select the therapy according to psoriasis severity, aiming that patients achieve longer remission periods and improve their quality of life. Biological markers for diagnosis and prognosis of psoriasis help to establish its severity and to monitor the therapeutic response; moreover, biomarkers of psoriasis assist clinicians in their therapeutic decision to treat psoriasis and to choose earlier and more adequate therapeutic strategies, avoiding or minimising worsening of psoriasis. With these markers, they would be able to monitor therapeutics, avoiding unnecessary therapeutic surcharge or changes to a more aggressive therapy. As any attempt to identify these biomarkers should be encouraged, in this review,we will debate published data concerning the proposal of biomarkers to evaluate severity and response to treatment of psoriasis vulgaris.展开更多
<span style="font-family:Verdana;">Chimaeras</span><span style="font-family:;" "=""><span style="font-family:Verdana;">, fish in the order Chimaerif...<span style="font-family:Verdana;">Chimaeras</span><span style="font-family:;" "=""><span style="font-family:Verdana;">, fish in the order Chimaeriformes, are among the rarest and least studied fish in the class Chondrichthyes (cartilaginous fish). Previous records have indicated that a species of chimaera known as the elephantfish, or cockfish, </span><i><span style="font-family:Verdana;">Callorhinchus callorynchus</span></i><span style="font-family:Verdana;">, may be found in marine waters off southeastern Brazil, as far north as the state of S<span style="font-size:10.0pt;font-family:"">ã</span>o Paulo. Here we report that </span><i><span style="font-family:Verdana;">C. callorynchus</span></i><span style="font-family:Verdana;">, caught with bottom gillnet, was found in an urban fish market in the city of Rio de Janeiro (~23<span style="white-space:nowrap;">˚</span>S). This and other records from a variety of places call into question the distribution limits of the American elephantfish in the southwestern Atlantic Ocean and whether, at least seasonally, this species may often be found as far north as the state of Rio de Janeiro. Because of scientific and conservation interests in the poorly known Chimaeriformes, we recommend long-term monitoring of the fish catch in ports along the southern Brazilian coast, to better understand the natural history of the intriguing chimeras.</span></span>展开更多
We have characterized the number of ovules per ovary (NoOV) in cacao plants originated from crossing the clones CCN 51 and TSH 1188 (segregating progeny) and determined the heritability of this characteristic in order...We have characterized the number of ovules per ovary (NoOV) in cacao plants originated from crossing the clones CCN 51 and TSH 1188 (segregating progeny) and determined the heritability of this characteristic in order to select plants with higher NoOV in this progeny. The NoOV was calculated as the average of 10 flowers per plant and ranged from 44.8 to 58.6 between the six clones (two parents and four clones belonging to their genealogy). In the progeny (n = 209 plants) the NoOV averaged 54.3 (range 44.1 to 67.8). The NoOV was distributed uniformly among the progeny indicating that this trait is conditioned by polygenes. Its heritability was estimated at 67.7%. The 32 plants with NoOV similar or superior to the genitor CCN 51 (highest amount among clones) were selected for use in the genetic improvement program. We showed that this population is suitable for genetic mapping, molecular marker identification and selection of superior cacao genotypes.展开更多
Background: Dengue is a Neglected tropical disease (NTDs) with high incidence in Brazil. This disease is caused by Dengue virus and is transmitted by Aedes aegypti mosquito. The search for new approaches for controlli...Background: Dengue is a Neglected tropical disease (NTDs) with high incidence in Brazil. This disease is caused by Dengue virus and is transmitted by Aedes aegypti mosquito. The search for new approaches for controlling of this disease is the subject of numerous studies. The aaNAT is a key enzyme in the metabolism of A. aegypti and is crucial in the sclerotization process, as well as regulation of circadian rhythm and inactivation of neurotransmitters. Computational techniques applied to studies of biological systems become an effective weapon in the mapping and management of 3D data structures, giving direction and guidance of potential ligands that can form stable complexes with targets of interest, using a Molecular Docking approach. The present study was conducted by a virtual screening, followed by docking calculations, in order to find molecules that could inhibit aaNAT. In this study, we used available compounds in SAM database (Bioinformatics and Medicinal Chemistry Laboratory—Southwest Bahia State University, Jequié-Bahia, Brazil), PubChem and ZINC. Results: The result of dockings with selected ligands showed good energy affinities, presenting potential inhibitory interactions with the enzyme active site. Conclusions: The Coa-S-acetyl-tryptamine and 3-indoleacriloil-coenzyme-A showed the same binding energies -8.9 Kcal/Mol and were described as possible inhibitors of aaNAT.展开更多
In this paper, a novel solid state Nitric Oxide (NO) sensor made of a spin trap (iron(II)-diethyldithiocarbamate complex, FeDETC) encapsulated in a siloxane-poly(oxypropylene) (PPO) matrix was developed. Nitric oxide ...In this paper, a novel solid state Nitric Oxide (NO) sensor made of a spin trap (iron(II)-diethyldithiocarbamate complex, FeDETC) encapsulated in a siloxane-poly(oxypropylene) (PPO) matrix was developed. Nitric oxide (NO), a free radical molecule, has numerous roles in various physiological functions, such as the regulation of blood pressure, immune response to bacterial infection, and nervous systems. Siloxane-polyether hybrid materials, for example siloxane-poly(oxypropylene) (PPO), are easy to prepare, transparent and flexible. The combination of all these characteristics in a unique material allows it to be used in several scientific and technological areas, including human health. NO radical is trapped in FeDETC, which allows its detection by electron paramagnetic resonance (EPR). FeDETC was added while PPO was a sol, which was then left in air for gelation. The novel sensor was dived directly into a solution of NO, when the NO-FeDETC complex was formed. Our results show that the novel sensor responds to NO, with similar sensitivity as previously published sensors. PPO sensors present a strong EPR signal and a high stability, keeping its signal for 45 days. We have studied ways to accelerate the NO release from the sensor, in order to study its potential as a drug delivery system. We observed an acceleration in NO release by using a modulated magnetic field of 40 G at 100 kHz;as well as by UV irradiation. Thermal induced NO release was also tested by heating NO-FeDETC PPO up to 50°C, with good results.展开更多
Aims We analyse here the variations in species composition and richness and the geographic ranges of the tree species occurring in south american subtropical atlantic and Pampean forests.our goals were to assess(i)the...Aims We analyse here the variations in species composition and richness and the geographic ranges of the tree species occurring in south american subtropical atlantic and Pampean forests.our goals were to assess(i)the floristic consistency of usual classifications based on vegetation physiognomy,climate and elevation;(ii)the leading role of temperature-related variables on the variations in species composition and richness;(iii)the predominance of species with tropical-subtropical ranges,possibly as a result of forest expansion over grasslands after the last glacial maximum(LGM);(iv)the restriction of most subtropical endemics to stressful habitats as a possible result of past forest refuges during the LGM.Methods The region was defined by the Tropic of Capricorn to the north,the rio de la Plata to the south,the atlantic shoreline to the east and the catchment areas of the upper Paranáand uruguay rivers to the west.multivariate analyses,multiple regression modelling and variance partition analyses were performed on a database containing 63994 occurrence records of 1555 tree species in 491 forest sites and 48 environmental variables.all species were also classified according to their known geographic range.Important Findingsa main differentiation in species composition and richness was observed between the eastern windward coastlands(rain and cloud forests)and western leeward hinterlands(Araucaria and semi-decid-uous forests).Pre-defined forest types on both sides were consistent with variations in tree species composition,which were significantly related to both environmental variables and spatial proximity,with extremes of low temperature playing a chief role.Tree species rich-ness declined substantially towards the south and also from rain to seasonal forests and towards the highland summits and sandy shores.species richness was significantly correlated with both minimum temperature and actual evapotranspiration.about 91%of the subtropical flora is shared with the much richer tropical flora,prob-ably extracting species that can cope with frost outbreaks.The 145 subtropical endemics were not concentrated in harsher habitats.展开更多
Aims Screening tree species in tropical rainforest according to their shade tolerance is important to efficiently manage the native trees of economic significance in secondary forest enrichment regimes.The objective o...Aims Screening tree species in tropical rainforest according to their shade tolerance is important to efficiently manage the native trees of economic significance in secondary forest enrichment regimes.The objective of this study was to determine the whole-plant light compensation point(WPLCP)and compare the phenotypic plasticity in relation to growth and carbon allocation of Cariniana legalis and Gallesia integrifolia seedlings under low light availability.Methods Seedlings were cultivated for 77 days under conditions of five photosynthetically active radiation(PAR)(0.02,1.1,2.3,4.5 and 5.9 mol photons m^(−2)day^(−1))in three replicates.Growth and carbon allocation variables were determined.Important Findings Growth rates of C.legalis were higher and lower than those of G.integrifolia under 1.1 and 5.9 mol photons m^(−2)day^(−1),respectively.The WPLCP differed significantly between the two species.In accordance with the criteria of the shade tolerance classification for these two tropical tree species,our results showed that C.legalis had lower WPLCP and phenotypic plasticity in terms of higher growth rates and greater shade tolerance than G.integrifolia.From a practical point of view,we demonstrated that the differential linkage between growth and changing PAR between the two species can become a useful tool for comparing and selecting tree species in forest enrichment projects.展开更多
文摘Kitchen sponges continue to be heavily used in Brazilian food services, even though they may be very contaminated. The objective of this study was to evaluate the microbiological contamination and the efficacy of two procedures for the disinfection of kitchen sponges used in Brazilian food services. Eighty sponges were collected from food services and then analyzed for the quantification heterotrophic microorganisms (HM), fecal coliforms (CF), Staphylococcus coagulase-positive (SA) microorganisms and to the investigation of the presence of Salmonella sp. (SAM). After that, the sponges were disinfected, separately, by either boiling water for five minutes or immersed in 200ppm sodium hypochlorite, for 10 minutes, added to a rinse with potable water. The results showed that sponges presented HM counts between 3.4 and 10.4 log CFU/sponge, with an average of 9.1 log CFU/sponge, and 76.25% of them presented CF with average counts of 8.4 log CFU/sponge. SA and SAM were found in 2.5% of samples. Both disinfection procedures were able to significantly reduce the bacterial counts, but the boiling method showed a greater reduction (99.9999%) than the method of disinfection by 200 ppm sodium hypochlorite (99.9%). Based on the results it was possible to conclude that kitchen sponges can be very contaminated, but simple disinfection procedure can be applied to significantly reduce the microbial contamination.
文摘Separately, it is well-documented that phytochromes (phys), gibberellin (GA) and abscisic acid (ABA) strongly control the seed germination in tomato. However, we hipothesized that phys interact with GA or ABA during this response. Thus, we make an analysis of seed germination of ABA deficient (sit), GA constitutive response (pro), phytochrome deficient (au) mutants as well as, specially, au sit and au pro double mutants of tomato?incubated in the dark or light conditions during 120 h [12 h intervals (i)]. Compared to au, which severely?reduced percentage germination (Gi%) and pro, which did not alter Gi%, au pro showed in the light enhanced Gi% and germination speed index (GSI) besides the reduced average germination time (AGT). Moreover, in the dark, germination of au pro was similar to pro. These results indicate that the mechanisms by which GA modulate germination in tomato are light dependent through the phy signaling, whereas intermediary values of Gi%, GSI and AGT in dark and light of au sit compared to au and sit single mutants indicate an additive effect of the au and sit mutations, suggesting that ABA and phy may act through the parallel signaling pathway.
文摘Above-optimal temperatures reduce yield in many crops, including tomato, largely because of the heat-sensitivity of their reproduction process. A full understanding of heat-stress (HS) response and thermotolerance of tomato reproduction is still lacking. Recently, using external application of the plant <span style="font-family:Verdana;">hormone ethylene, it was demonstrated that ethylene plays a role in</span><span style="font-family:Verdana;"> heat-tolerance of tomato pollen (the male reproductive cells). In order to expand our understanding on involvement of ethylene in tomato pollen thermotolerance, </span><span style="font-family:Verdana;">we analyzed the response of wild type and ethylene-related tomato mutant</span> <span style="font-family:Verdana;">plants to HS, at physiological and molecular levels. We report that mild</span><span style="font-family:Verdana;"> chronic </span><span style="font-family:Verdana;">HS conditions highly reduce the number of viable and germinating pollen </span><span style="font-family:Verdana;">grains as well as the production of seeded fruits in wild type tomato plants, while no significant reduction was detected/observed in pollen quality, number of seeded fruits and seeds per fruit in plants of the ethylene over-producer mutant epinastic. Our findings suggest that ethylene is involved in thermotolerance of tomato reproduction, pointing to an effect on pollen viability and </span><span style="font-family:Verdana;">germination potential, highlighting candidate genes involved in pollen re</span><span style="font-family:Verdana;">sponse to HS (like </span><i><span style="font-family:Verdana;">SlHSP17</span></i><span style="font-family:Verdana;">, </span><i><span style="font-family:Verdana;">SlHSP101</span></i><span style="font-family:Verdana;">, </span><i><span style="font-family:Verdana;">SlMBF1</span></i><span style="font-family:Verdana;">) and suggesting directions for further studies.</span>
文摘In Diatraea saccharalis larvae, the Malpighian tubules are found along the digestive tube, extending from the middle mesenteric region to the end of the posterior intestine, where they come in contact with the rectum to form the cryptonephridium. Scanning and transmission electron microscopy of non-parasitized and parasitized larvae by Cotesia flavipes have indicated that the tubules consist of secretory and reabsorption cells. In parasitized larvae, the occurrence of hemocytes and teratocytes around the tubules is indicative of their role in immunological defense;however, they were not observed in non-parasitized larvae. At day 9 of parasitism, the mitochondria-containing vacuoles and myelin-like figures show signs of degeneration. The results of this study have confirmed that C. flavipes manipulates the physiology and biochemistry of D. saccharalis because the Malpighian tubules of the parasitized larvae remain active until the parasitoid completes its pupal stage and is released from the host organism.
基金FAPEMIG (Funda■o de Amparo à Pesquisa do Estado de Minas Gerais)CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico)PRONEX (Grupos de Excelência)
文摘AIM: To evaluate in bile duct ligated rats whether there were progressive alterations of renal function without changes in histopathology. METHODS: Male Wistar rats were submitted to sham-surgery or bile duct ligation (BDL) and divided according to the post-procedure time (2, 4 and 6-wk). To determine renal function parameters, rats wereplaced in metabolic cages and, at the end of the experiment, blood and urine samples were obtained. Histology and hydroxyproline content were analyzed in liver and renal tissue. RESULTS: Rats with 2 wk of BDL increased free water clearance (P = 0.02), reduced urinary osmolality (P = 0.03) and serum creatinine (P = 0.01) in comparison to the sham group. In contrast, rats at 6 wk of BDL showed features of HRS, including signif icant increase in serum creatinine and reductions in creatinine clearance, water excretion and urinary sodium concentration. Rats with 4 wk of BDL exhibited an intermediate stage of renal dysfunction. Progressive hepatic f ibrosis according to post-procedure time was confirmed by histology. The increased levels of liver hydroxyproline contrasted with the absence of structural changes in the kidney, as assessed by histology and unchanged hydroxyproline content in renal tissue. CONCLUSION: Our data show that BDL produced progressive renal dysfunction without structural changes in the kidney, characterizing HRS. The present model will be useful to understand the pathophysiology of HRS.
文摘Development of type 2 diabetes has been linked to β-cell failure coupled with insulin resistance and obesity. Adipose tissue, known as the fat store, secretes a number of hormones and proteins collectively termed adipokines some of which regulate insulin sensitivity. Dysregulation in the secretion of adipokines has been linked to insulin resistance and type 2 diabetes. In this review, we sum-marized evidence of the role of adipokines with focus on leptin, adiponectin, adipsin, visfatin and apelin in the pathogenesis of type 2 diabetes and discussed the potential of saponins to modify the ill-regulated adipokines secretions, which could promote the use of this class of phytochemicals as potential antidiabetics agents.
文摘Cacao is a crop of global relevance that faces constant demands for improved bean yield.However,little is known about the genomic regions controlling the crop yield and genes involved in cacao bean filling.Hence,to identify the quantitative trait loci(QTL)associated with cacao yield and bean filling,we performed a QTL mapping in a segregating mapping population comprising 459 trees of a cross between‘TSH 1188’and‘CCN 51’.All variables showed considerable phenotypic variation and had moderate to high heritability values.We identified 24 QTLs using a genetic linkage map that contains 3526 single nucleotide polymorphism(SNP)markers.Haplotype analysis at the significant QTL region on chromosome IV pointed to the alleles from the maternal parent,‘TSH 1188’,as the ones that affect the cacao yield components the most.The recombination events identified within these QTL regions allowed us to identify candidate genes that may take part in the different steps of pod growth and bean filling.Such candidate genes seem to play a significant role in the source-to-sink transport of sugars and amino acids,and lipid metabolism,such as fatty acid production.The SNP markers mapped in our study are now being used to select potential highyielding cacao varieties through marker-assisted selection in our existing cacao-breeding experiments.
文摘This study aimed to observe the viability of the pollen grains of Malpighia emarginata DC. (West Indian cherry) and the action of a lectin in their germination. Lectins are proteins that specifically interact with carbohydrates, but don’t modify them and bind with high affinity and specificity, promoting a transfer of information that is clearly central to many cellular processes in living beings. For the viability test was used aniline blue in lactophenol. The in vitro germination test used was the hanging drop method, in control medium containing sucrose, boric acid, calcium nitrate and agar. The experiment dealt with three different treatments in order to pollen germination: growing medium without addition of lectin, with 1.0 μg/ml and with 3.0 μg/ml CPL lectin. This lectin is extracted from seeds of Crotalaria pallida L.-Leguminosae. Data on pollen grains were analyzed by one-way ANOVA, with 95% reliability and comparison of averages by Turkey test at 5% probability. It was found that despite previous high viability of the pollen grains (c. 70%), a germinability rate has been low, yet exceptionally larger in pollen samples placed on a growing medium with addition of 3.0 μg/ml of CPL lectin (24%). There was no significant difference among the pollen grains germinate in medium without lectin and those in medium with the addition of only 1.0 μg/ml. According to data obtained in the treatments, CPL lectin, with concentration of 3.0 μg/ml, influenced the formation of the pollen tube and thus more pollen germinated in Malpighia emarginata.
文摘Cellulases are enzymes responsible for the degradation of cellulose, the major compound in plant cells. Cellulose is a polysaccharide composed of several glucose units linked together by chemical bonds. Cellulases, such as endoglucanases, beta-glucosidase and exoglucanases, break the chemical bonds between the glucose units. Fungi, including the endophytic species, can be great cellulase producers. This study aimed to evaluate cellulase production by four endophytic strains of Trichoderma reesei semi-solid media containing sugarcane bagasse, supplemented or not with salts. Two fermentations were carried out for 43 days. Samples were taken every seven days to obtain production peaks. The enzymes were characterized by their optimum pH and temperature of activity and stability upon incubation in the presence of ions, pH and temperature variations. The results showed that the endophytic strains FB1, FB2, FB3 and FB4 of Trichoderma reesei produce cellulases in a sugarcane bagasse medium, supplemented or not with salts, at pH 5.5 and 30°C. The supplemented medium proved to be more appropriate to induce cellulase production after 29 days of fermentation, with FB4 having the best yield: 16.32 ± 2.65 IU/gram of fermented substrate.
基金supported by grants from Fundacao de Amparo a Ciencia e Tecnologia do Estado de Pernambuco(FACEPE)(grant 09/2017).
文摘Mayaro virus is an emergent alphavirus that infects humans,leading to Mayaro fever.Approximately fifty percent of infected patients develop arthritis symptoms in the recovery phase,a phase that can last up to a year.The literature about Mayaro virus infection and its immune response is scarce,which may hamper the development of treatment strategies.We summarize changes in cytokines and chemokines in the acute and recovery phase in Mayaro virus infected patients,and relate this molecular characterization with the immune response.VEGF and IL-12/p70 show pronounced changes in patients in the acute phase,suggesting the development of cellular immunity and Th1 response.IL-6,IL-7,CXCL8/IL-8,IL-13,IL-17,and IFN-γare elevated in patients with arthritis symptoms in the long-term recovery phase,which may be related to the continuous inflammatory process,a possible Th2 inhibiting and promoting Th17 process.Although few studies discuss the issue,with a small number of patients and different backgrounds,inflammatory and immune response and manifestations seem to be closely linked.This information may help to develop the appropriate treatment strategies in Mayaro virus infection.Therefore,we analyzed and summarized data available in literature.
基金Brazilian institutions and research agencies FUNCAP,URCA,UFRPE,ICMBio,UFSM and FIOCRUZ
文摘To establish the chemical profile, and to evaluate the antibacterial and modulatory activity of the ethanolic extracts of the stalk’s inner bark and heartwood of Secondatia floribunda.MethodsQuantification of total phenols and flavonoids was determined by the Folin-Ciocalteu method and aluminum chloride, respectively. Phenolic compounds were identified and quantified by HPLC-DAD (High Performance Liquid Chromatography-Diodearray Detector) and the Infrared Spectroscopy was performed using the measure by Attenuated Total Reflectance with Fourier Transform (ATR-FTIR). Antibacterial assays for determination of the Minimum Inhibitory Concentration (MIC) and modification of aminoglycosides were performed by microdilution.ResultsInfrared spectra showed similar characteristics, having among its main absorption bands hydroxyl group (OH). The antibacterial activity showed clinically significant results for the strains of Staphylococcus aureus and Escherichia coli. In modulation assay, synergic and antagonistic effect for both extracts was observed. Heartwood extract in combination with antibiotics showed a significant MIC reduction at 19.8% (P < 0.000 1)-79.3% (P < 0.01).ConclusionsThis study is the first report of chemical and biological information of Secondatia floribunda suggesting that it is clinically relevant source of a new antibacterial therapy, especially due to the presence of significant levels of phenolic compounds.
文摘The apple is the second most important fruit in Brazil. However, apple cultivars are susceptible to several diseases that can cause losses after harvesting. Bitter rot is caused by the fungus Colletotrichum gloeosporioides and is one of the most damaging summer diseases. The goal of this work was to evaluate the behavior of this fungus in four apple cultivars grown in Brazil (Fuji, Gala, Golden and Green) under two treatments: direct inoculation and isolated fungus. The fungus was isolated by taking fragments from infected fruits, which were stored on Potato Dextrose Agar (PDA) in a laboratory. For the direct treatment, the fungus was removed from infected fruits and directly inoculated into healthy fruits. After inoculation, the fruits were kept at room temperature and the halos of degradation were evaluated every 48 hours. The results demonstrated that direct inoculation was more pathogenic, that the Gala cultivar was the most resistant to the pathogen, and that the Golden cultivar was the most susceptible.
文摘The SONE oil/water was prepared using the pseudo-ternary phase diagram, using a low energy method with phase inversion by changing the composition. In order to optimize the preparation of SONE, three speeds were used in the agitator arm and two different rods. The particle size and polydispersity index were determined by Dynamic Light Scattering (DLS) and the stability test by the freeze-thaw cycle. Angiogenesis in chicken embryo egg chorioallantoic membrane and zebrafish (<em>Danio rerio</em>) embryotoxicity was performed. The lower stirring speed and propeller shaft induced smaller particle size (550.2 nm). Regarding angiogenesis, there was a statistically significant difference for all the evaluated parameters (length, caliber, junctions, and number of blood vessel complexes) and the result was higher in SONE when compared to the inhibition control (Dexamethasone), but lower than the induction control (Regederm<span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;"><sup>®</sup></span>) and there was no statistically significant difference between SONE and distilled water. It was observed that the exposure of the zebrafish embryos to SONE caused an increase in the mortality rate dependent on time and concentration. The LC<sub>50</sub> for SONE decreased statistically with increasing exposure (p-value = 0.046). Heart rate decreased significantly with increasing concentration at all exposure times (p-value < 0.05), as a result of progressive embryo mortality. The hatching rate was late until the concentration of 0.0193 mg/mL and no hatching rate was verified from that concentration. Exposure of zebrafish embryos to different concentrations of SONE induced malformations such as spinal changes, pericardial edema and yolk sac edema, but there was no significant difference in the malformation rate of embryos exposed to SONE when compared to the control group. The SONE produced remained stable in the freeze-thaw cycle, with changes only in pH. Despite the low results for embryotoxicity, further studies are needed, aiming at the ideal formulation for angiogenesis purposes.
文摘Psoriasis is a chronic, recurrent inflammatory cutaneous disease. Psoriasis patients alternate between periods of remission and periods of exacerbation of the disease. Usually, psoriasis severity is clinically evaluated using tools like Psoriasis Area and Severity Index that present some limitations and subjectivity. Clinicians select the therapy according to psoriasis severity, aiming that patients achieve longer remission periods and improve their quality of life. Biological markers for diagnosis and prognosis of psoriasis help to establish its severity and to monitor the therapeutic response; moreover, biomarkers of psoriasis assist clinicians in their therapeutic decision to treat psoriasis and to choose earlier and more adequate therapeutic strategies, avoiding or minimising worsening of psoriasis. With these markers, they would be able to monitor therapeutics, avoiding unnecessary therapeutic surcharge or changes to a more aggressive therapy. As any attempt to identify these biomarkers should be encouraged, in this review,we will debate published data concerning the proposal of biomarkers to evaluate severity and response to treatment of psoriasis vulgaris.
文摘<span style="font-family:Verdana;">Chimaeras</span><span style="font-family:;" "=""><span style="font-family:Verdana;">, fish in the order Chimaeriformes, are among the rarest and least studied fish in the class Chondrichthyes (cartilaginous fish). Previous records have indicated that a species of chimaera known as the elephantfish, or cockfish, </span><i><span style="font-family:Verdana;">Callorhinchus callorynchus</span></i><span style="font-family:Verdana;">, may be found in marine waters off southeastern Brazil, as far north as the state of S<span style="font-size:10.0pt;font-family:"">ã</span>o Paulo. Here we report that </span><i><span style="font-family:Verdana;">C. callorynchus</span></i><span style="font-family:Verdana;">, caught with bottom gillnet, was found in an urban fish market in the city of Rio de Janeiro (~23<span style="white-space:nowrap;">˚</span>S). This and other records from a variety of places call into question the distribution limits of the American elephantfish in the southwestern Atlantic Ocean and whether, at least seasonally, this species may often be found as far north as the state of Rio de Janeiro. Because of scientific and conservation interests in the poorly known Chimaeriformes, we recommend long-term monitoring of the fish catch in ports along the southern Brazilian coast, to better understand the natural history of the intriguing chimeras.</span></span>
文摘We have characterized the number of ovules per ovary (NoOV) in cacao plants originated from crossing the clones CCN 51 and TSH 1188 (segregating progeny) and determined the heritability of this characteristic in order to select plants with higher NoOV in this progeny. The NoOV was calculated as the average of 10 flowers per plant and ranged from 44.8 to 58.6 between the six clones (two parents and four clones belonging to their genealogy). In the progeny (n = 209 plants) the NoOV averaged 54.3 (range 44.1 to 67.8). The NoOV was distributed uniformly among the progeny indicating that this trait is conditioned by polygenes. Its heritability was estimated at 67.7%. The 32 plants with NoOV similar or superior to the genitor CCN 51 (highest amount among clones) were selected for use in the genetic improvement program. We showed that this population is suitable for genetic mapping, molecular marker identification and selection of superior cacao genotypes.
文摘Background: Dengue is a Neglected tropical disease (NTDs) with high incidence in Brazil. This disease is caused by Dengue virus and is transmitted by Aedes aegypti mosquito. The search for new approaches for controlling of this disease is the subject of numerous studies. The aaNAT is a key enzyme in the metabolism of A. aegypti and is crucial in the sclerotization process, as well as regulation of circadian rhythm and inactivation of neurotransmitters. Computational techniques applied to studies of biological systems become an effective weapon in the mapping and management of 3D data structures, giving direction and guidance of potential ligands that can form stable complexes with targets of interest, using a Molecular Docking approach. The present study was conducted by a virtual screening, followed by docking calculations, in order to find molecules that could inhibit aaNAT. In this study, we used available compounds in SAM database (Bioinformatics and Medicinal Chemistry Laboratory—Southwest Bahia State University, Jequié-Bahia, Brazil), PubChem and ZINC. Results: The result of dockings with selected ligands showed good energy affinities, presenting potential inhibitory interactions with the enzyme active site. Conclusions: The Coa-S-acetyl-tryptamine and 3-indoleacriloil-coenzyme-A showed the same binding energies -8.9 Kcal/Mol and were described as possible inhibitors of aaNAT.
基金This work received financial support from FAPESP,CNPq and CAPES.
文摘In this paper, a novel solid state Nitric Oxide (NO) sensor made of a spin trap (iron(II)-diethyldithiocarbamate complex, FeDETC) encapsulated in a siloxane-poly(oxypropylene) (PPO) matrix was developed. Nitric oxide (NO), a free radical molecule, has numerous roles in various physiological functions, such as the regulation of blood pressure, immune response to bacterial infection, and nervous systems. Siloxane-polyether hybrid materials, for example siloxane-poly(oxypropylene) (PPO), are easy to prepare, transparent and flexible. The combination of all these characteristics in a unique material allows it to be used in several scientific and technological areas, including human health. NO radical is trapped in FeDETC, which allows its detection by electron paramagnetic resonance (EPR). FeDETC was added while PPO was a sol, which was then left in air for gelation. The novel sensor was dived directly into a solution of NO, when the NO-FeDETC complex was formed. Our results show that the novel sensor responds to NO, with similar sensitivity as previously published sensors. PPO sensors present a strong EPR signal and a high stability, keeping its signal for 45 days. We have studied ways to accelerate the NO release from the sensor, in order to study its potential as a drug delivery system. We observed an acceleration in NO release by using a modulated magnetic field of 40 G at 100 kHz;as well as by UV irradiation. Thermal induced NO release was also tested by heating NO-FeDETC PPO up to 50°C, with good results.
基金Brazilian government research agencies Conselho Nacional de Desenvolvimento Científixo e Tecnológico(CNPq,grant number 301644/88-8)Royal Botanic Gardens Kew for the Kew Latin America Research FellowshipNew York Botanical Garden.
文摘Aims We analyse here the variations in species composition and richness and the geographic ranges of the tree species occurring in south american subtropical atlantic and Pampean forests.our goals were to assess(i)the floristic consistency of usual classifications based on vegetation physiognomy,climate and elevation;(ii)the leading role of temperature-related variables on the variations in species composition and richness;(iii)the predominance of species with tropical-subtropical ranges,possibly as a result of forest expansion over grasslands after the last glacial maximum(LGM);(iv)the restriction of most subtropical endemics to stressful habitats as a possible result of past forest refuges during the LGM.Methods The region was defined by the Tropic of Capricorn to the north,the rio de la Plata to the south,the atlantic shoreline to the east and the catchment areas of the upper Paranáand uruguay rivers to the west.multivariate analyses,multiple regression modelling and variance partition analyses were performed on a database containing 63994 occurrence records of 1555 tree species in 491 forest sites and 48 environmental variables.all species were also classified according to their known geographic range.Important Findingsa main differentiation in species composition and richness was observed between the eastern windward coastlands(rain and cloud forests)and western leeward hinterlands(Araucaria and semi-decid-uous forests).Pre-defined forest types on both sides were consistent with variations in tree species composition,which were significantly related to both environmental variables and spatial proximity,with extremes of low temperature playing a chief role.Tree species rich-ness declined substantially towards the south and also from rain to seasonal forests and towards the highland summits and sandy shores.species richness was significantly correlated with both minimum temperature and actual evapotranspiration.about 91%of the subtropical flora is shared with the much richer tropical flora,prob-ably extracting species that can cope with frost outbreaks.The 145 subtropical endemics were not concentrated in harsher habitats.
基金Marcelo S.Mielke gratefully acknowledge CNPq(Brazilian National Council for Scientific and Technological Development)for the award of fellowship of scientific productivity(305477/2018-8).
文摘Aims Screening tree species in tropical rainforest according to their shade tolerance is important to efficiently manage the native trees of economic significance in secondary forest enrichment regimes.The objective of this study was to determine the whole-plant light compensation point(WPLCP)and compare the phenotypic plasticity in relation to growth and carbon allocation of Cariniana legalis and Gallesia integrifolia seedlings under low light availability.Methods Seedlings were cultivated for 77 days under conditions of five photosynthetically active radiation(PAR)(0.02,1.1,2.3,4.5 and 5.9 mol photons m^(−2)day^(−1))in three replicates.Growth and carbon allocation variables were determined.Important Findings Growth rates of C.legalis were higher and lower than those of G.integrifolia under 1.1 and 5.9 mol photons m^(−2)day^(−1),respectively.The WPLCP differed significantly between the two species.In accordance with the criteria of the shade tolerance classification for these two tropical tree species,our results showed that C.legalis had lower WPLCP and phenotypic plasticity in terms of higher growth rates and greater shade tolerance than G.integrifolia.From a practical point of view,we demonstrated that the differential linkage between growth and changing PAR between the two species can become a useful tool for comparing and selecting tree species in forest enrichment projects.