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1.
Nutrients ; 14(3)2022 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-35276790

RESUMEN

Diabetes mellitus (DM) is a worldwide health concern, and projections state that cases will reach 578 million by 2030. Adjuvant therapies that can help the standard treatment and mitigate DM effects are necessary, especially those using nutritional supplements to improve glycemic control. Previous studies suggest creatine supplementation as a possible adjuvant therapy for DM, but they lack the evaluation of potential morphological parameters alterations and tissue injury caused by this compound. The present study aimed to elucidate clinical, histomorphometric, and histopathological consequences and the cellular oxidative alterations of creatine supplementation in streptozotocin (STZ)-induced type 1 DM rats. We could estimate whether the findings are due to DM or the supplementation from a factorial experimental design. Although creatine supplementation attenuated some biochemical parameters, the morphological analyses of pancreatic and renal tissues made clear that the supplementation did not improve the STZ-induced DM1 injuries. Moreover, creatine-supplemented non-diabetic animals were diagnosed with pancreatitis and showed renal tubular necrosis. Therefore, even in the absence of clinical symptoms and unaltered biochemical parameters, creatine supplementation as adjuvant therapy for DM should be carefully evaluated.


Asunto(s)
Creatina , Diabetes Mellitus Experimental , Animales , Creatina/farmacología , Creatina/uso terapéutico , Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Mellitus Experimental/patología , Suplementos Dietéticos , Riñón/patología , Páncreas , Ratas , Ratas Wistar , Estreptozocina
2.
Life Sci ; 295: 120393, 2022 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-35167880

RESUMEN

AIMS: Hyperbaric oxygen (HBO) therapy has been widely used for the adjunctive treatment of diabetic wounds, and is currently known to influence left ventricular (LV) function. However, morphological and molecular repercussions of the HBO in the diabetic myocardium remain to be described. We aimed to investigate whether HBO therapy would mitigate adverse LV remodeling caused by streptozotocin (STZ)-induced diabetes. MAIN METHODS: Sixty-day-old Male Wistar rats were divided into four groups: Control (n = 8), HBO (n = 7), STZ (n = 10), and STZ + HBO (n = 8). Diabetes was induced by a single STZ injection (60 mg/kg, i.p.). HBO treatment (100% oxygen at 2.5 atmospheres absolute, 60 min/day, 5 days/week) lasted for 5 weeks. LV morphology was evaluated using histomorphometry. Gene expression analyzes were performed for LV collagens I (Col1a1) and III (Col3a1), matrix metalloproteinases 2 (Mmp2) and 9 (Mmp9), and transforming growth factor-ß1 (Tgfb1). The Immunoexpression of cardiac tumor necrosis factor-α (TNF-α) and vascular endothelial growth factor (VEGF) were also quantified. KEY FINDINGS: HBO therapy prevented LV concentric remodeling, heterogeneous myocyte hypertrophy, and fibrosis in diabetic rats associated with attenuation of leukocyte infiltration. HBO therapy also increased Mmp2 gene expression, and inhibited the induction of Tgfb1 and Mmp9 mRNAs caused by diabetes, and normalized TNF-α and VEGF protein expression. SIGNIFICANCE: HBO therapy had protective effects for the LV structure in STZ-diabetic rats and ameliorated expression levels of genes involved in cardiac collagen turnover, as well as pro-inflammatory and pro-angiogenic signaling.


Asunto(s)
Oxigenoterapia Hiperbárica/métodos , Remodelación Ventricular/fisiología , Animales , Cardiotónicos/farmacología , Diabetes Mellitus Experimental/inducido químicamente , Diabetes Mellitus Experimental/fisiopatología , Fibrosis , Ventrículos Cardíacos/metabolismo , Masculino , Metaloproteinasa 2 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/metabolismo , Miocardio/metabolismo , Ratas , Ratas Wistar , Estreptozocina/farmacología , Factor de Crecimiento Transformador beta1/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismo , Función Ventricular Izquierda/efectos de los fármacos
3.
PLoS One ; 15(10): e0240536, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33057447

RESUMEN

Nucleic acid detection by electrophoresis is still a quick and accessible technique for many diagnosis methods, primarily at research laboratories or at the point of care units. Standard protocols detect DNA/RNA molecules through specific bound chemical dyes using a UV-transilluminator or UV-photo documentation system. However, the acquisition costs and availability of these devices, mainly the ones with photography and internet connection capabilities, can be prohibitive, especially in developing countries public health units. Also, ultraviolet radiation is a common additional risk factor to professionals that use electrophoresis-based nucleic acid detection. With that in mind, this work describes the development of a low-cost DNA/RNA detection smart system capable of obtaining qualitative and semi-quantitative data from gel analysis. The proposed device explores the visible light absorption range of commonly used DNA/RNA dyes using readily available parts, and simple manufacturing processes, such as light-emitting diodes (LEDs) and 3D impression. By applying IoT techniques, our system covers a wide range of color spectrum in order to detect bands from various commercially used dyes, using Bluetooth communication and a smartphone for hardware control, image capturing, and sharing. The project also enables process scalability and has low manufacturing and maintenance costs. The use of LEDs at the visible spectrum can achieve very reproducible images, providing a high potential for rapid and point-of-care diagnostics as well as applications in several fields such as healthcare, agriculture, and aquaculture.


Asunto(s)
ADN/aislamiento & purificación , Sistemas de Atención de Punto/economía , ARN/aislamiento & purificación , Costos y Análisis de Costo , ADN/química , Electroforesis en Gel de Agar/economía , Electroforesis en Gel de Agar/instrumentación , Diseño de Equipo , Colorantes Fluorescentes/química , Luz , ARN/química , Teléfono Inteligente , Programas Informáticos
4.
Front Microbiol ; 11: 2058, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32983042

RESUMEN

Cryptococcosis is a fungal infection caused mainly by the pathogenic yeasts Cryptococcus neoformans and Cryptococcus gattii. The infection initiates with the inhalation of propagules that are then deposited in the lungs. If not properly treated, cryptococci cells can disseminate and reach the central nervous system. The current recommended treatment for cryptococcosis employs a three-stage regimen, with the administration of amphotericin B, flucytosine and fluconazole. Although effective, these drugs are often unavailable worldwide, can lead to resistance development, and may display toxic effects on the patients. Thus, new drugs for cryptococcosis treatment are needed. Recently, an iridoid named plumieridine was found in Allamanda polyantha seed extract; it exhibited antifungal activity against C. neoformans with a MIC of 250 µg/mL. To address the mode of action of plumieridine, several in silico and in vitro experiments were performed. Through a ligand-based a virtual screening approach, chitinases were identified as potential targets. Confirmatory in vitro assays showed that C. neoformans cell-free supernatant incubated with plumieridine displayed reduced chitinase activity, while chitinolytic activity was not inhibited in the insoluble cell fraction. Additionally, confocal microscopy revealed changes in the distribution of chitooligomers in the cryptococcal cell wall, from a polarized to a diffuse cell pattern state. Remarkably, further assays have shown that plumieridine can also inhibit the chitinolytic activity from the supernatant and cell-free extracts of bacteria, insect and mouse-derived macrophage cells (J774.A1). Together, our results suggest that plumieridine can be a broad-spectrum chitinase inhibitor.

5.
Sci Rep ; 9(1): 15741, 2019 10 31.
Artículo en Inglés | MEDLINE | ID: mdl-31673065

RESUMEN

Reactive oxygen species (ROS) are byproducts of aerobic metabolism and may cause oxidative damage to biomolecules. Plants have a complex redox system, involving enzymatic and non-enzymatic compounds. The evolutionary origin of enzymatic antioxidant defense in plants is yet unclear. Here, we describe the redox gene network for A. thaliana and investigate the evolutionary origin of this network. We gathered from public repositories 246 A. thaliana genes directly involved with ROS metabolism and proposed an A. thaliana redox gene network. Using orthology information of 238 Eukaryotes from STRINGdb, we inferred the evolutionary root of each gene to reconstruct the evolutionary history of A. thaliana antioxidant gene network. We found two interconnected clusters: one formed by SOD-related, Thiol-redox, peroxidases, and other oxido-reductase; and the other formed entirely by class III peroxidases. Each cluster emerged in different periods of evolution: the cluster formed by SOD-related, Thiol-redox, peroxidases, and other oxido-reductase emerged before opisthokonta-plant divergence; the cluster composed by class III peroxidases emerged after opisthokonta-plant divergence and therefore contained the most recent network components. According to our results, class III peroxidases are in expansion throughout plant evolution, with new orthologs emerging in each evaluated plant clade divergence.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Evolución Molecular , Redes Reguladoras de Genes/genética , Peroxidasas/metabolismo , Antioxidantes/química , Antioxidantes/metabolismo , Proteínas de Arabidopsis/genética , Oxidación-Reducción , Peroxidasas/genética , Especies Reactivas de Oxígeno/metabolismo
6.
BMC Struct Biol ; 19(1): 8, 2019 04 18.
Artículo en Inglés | MEDLINE | ID: mdl-30999895

RESUMEN

BACKGROUND: White Spot Syndrome Virus (WSSV) is an enveloped double-stranded DNA virus which causes mortality of several species of shrimp, being considered one of the main pathogens that affects global shrimp farming. This virus presents a complex genome of ~ 300 kb and viral isolates that present genomes with great identity. Despite this conservation, some variable regions in the WSSV genome occur in coding regions, and these putative proteins may have some relationship with viral adaptation and virulence mechanisms. Until now, the functions of these proteins were little studied. In this work, sequences and putative proteins encoded by WSSV variable regions were characterized in silico. RESULTS: The in silico approach enabled determining the variability of some sequences, as well as the identification of some domains resembling the Formin homology 2, RNA recognition motif, Xeroderma pigmentosum group D repair helicase, Hemagglutinin and Ankyrin motif. The information obtained from the sequences and the analysis of secondary and tertiary structure models allow to infer that some of these proteins possibly have functions related to protein modulation/degradation, intracellular transport, recombination and endosome fusion events. CONCLUSIONS: The bioinformatics approaches were efficient in generating three-dimensional models and to identify domains, thereby enabling to propose possible functions for the putative polypeptides produced by the ORFs wsv129, wsv178, wsv249, wsv463a, wsv477, wsv479, wsv492, and wsv497.


Asunto(s)
Sistemas de Lectura Abierta , Penaeidae/virología , Proteínas Virales/química , Virus del Síndrome de la Mancha Blanca 1/fisiología , Adaptación Biológica , Animales , Simulación por Computador , Explotaciones Pesqueras , Genoma Viral , Modelos Moleculares , Dominios Proteicos , Estructura Secundaria de Proteína , Estructura Terciaria de Proteína , Virulencia , Virus del Síndrome de la Mancha Blanca 1/genética
7.
PLoS One ; 14(2): e0211643, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30716140

RESUMEN

The aim of this study was to compare the treatment effects of laser photobiomodulation (LPBM) therapy and aerobic exercise on the biomechanical properties, tissue morphology and the expression of tendon matrix molecules during early remodeling of Achilles tendon (AT) injury in diabetic rats. Animals were randomly assigned to five groups: injured non diabetic (I, n = 15), injured diabetic (ID, n = 15), injured diabetic plus LPBM (IDL, n = 16), injured diabetic plus aerobic exercise (IDE, n = 16) and injured diabetic plus aerobic exercise and LPBM (IDEAL, n = 17). Type 1 diabetes was induced via a single intravenous injection of Streptozotocin at a dose of 40 mg/kg. A partial tenotomy was performed in the right AT. LPBM was performed with an indium-gallium-aluminum-phosphide 660 nm 10 mW laser device (spot size 0.04 cm2, power density 250 mW/cm2, irradiation duration 16 s, energy 0.16 J, energy density 4 J/cm2) on alternate days for a total of 9 sessions over 3 weeks (total energy 1.44 J), using a stationary contact technique to a single point over the dorsal aspect of the AT. Moderate aerobic exercise was performed on a motorized treadmill (velocity 9 m/min for 60 minutes). At 3 weeks post-injury, biomechanical analyzes as well as assessment of fibroblast number and orientation were performed. Collagen 1 (Col1) and 3 (Col3) and matrix metalloproteinases (MMPs) -3 and 13 protein distributions were studied by immunohistochemistry; while Col1 and Col3 and MMP-2 and 9 gene expression were assessed by quantitative RT-PCR (qRT-PCR). IDEAL exhibited significant increases in several biomechanical parameters in comparison to the other groups. Moreover, IDEAL presented stronger Col1 immunoreactivity when compared to ID, and weaker Col3 immunoreactivity than IDE. Both IDL and IDEAL demonstrated weaker expression of MMP-3 in comparison to I, while IDL presented no expression of MMP-13 when compared to ID. ID, IDL and IDE showed an increased number of fibroblasts in comparison to I, while IDEAL decreased the number of these cells in comparison to ID and IDE. IDL and IDEAL groups exhibited decreased angular dispersion among the fibroblasts when compared to I. The gene expression results showed that IDE demonstrated a downregulation in Col1 mRNA expression in comparison to I and ID. IDEAL demonstrated upregulation of Col1 mRNA expression when compared to IDL or IDE alone and increased MMP-2 expression when compared to IDL and IDE. MMP-9 expression was upregulated in IDEAL when compared to I, IDL and IDE. Our results suggest a beneficial interaction of combining both treatment strategies i.e., aerobic exercise and LPBM, on the biomechanical properties, tissue morphology and the expression of matrix molecules in diabetic tendons.


Asunto(s)
Tendón Calcáneo/fisiopatología , Diabetes Mellitus Experimental/fisiopatología , Diabetes Mellitus Tipo 1/fisiopatología , Traumatismos de los Tendones/terapia , Tendón Calcáneo/metabolismo , Animales , Colágeno Tipo I/metabolismo , Colágeno Tipo III/metabolismo , Diabetes Mellitus Experimental/inducido químicamente , Diabetes Mellitus Experimental/etiología , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 1/inducido químicamente , Diabetes Mellitus Tipo 1/complicaciones , Diabetes Mellitus Tipo 1/metabolismo , Fibroblastos/metabolismo , Terapia por Luz de Baja Intensidad/métodos , Masculino , Metaloendopeptidasas/metabolismo , ARN Mensajero/metabolismo , Ratas , Ratas Wistar , Estreptozocina/farmacología , Traumatismos de los Tendones/etiología , Traumatismos de los Tendones/metabolismo , Traumatismos de los Tendones/fisiopatología , Regulación hacia Arriba/fisiología , Cicatrización de Heridas/fisiología
8.
Anim Reprod ; 15(1): 84-92, 2018 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-33365100

RESUMEN

This study aimed to develop protocols for the extraction of sperm proteins from Moxotó goats (Capra hircus) and to compare the resulting proteomic maps. The sperm proteins were isolated using an extraction buffer containing 7 M urea and 2 M thiourea, 20 mM DTT, and one of the following detergents: 1% or 4% CHAPS; 1% or 4% SDS; 1% or 4% Triton X-100; or a combination of CHAPS and SDS. The 1-DE and 2-DE profiles of the isolated proteins revealed that the various isolation methods were efficient. Qualitative and quantitative differences in the 1-DE and 2-DE profiles were observed. 2-DE maps indicated that the amount and diversity of proteins visualized depended on the detergent that was used. Furthermore, this work revealed that the combination of detergents increased the resolution of some spots and retained the characteristics of the individual detergents, depending on their concentrations.

9.
Peptides ; 68: 3-10, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25805002

RESUMEN

A new antimicrobial peptide, herein named Stigmurin, was selected based on a transcriptomic analysis of the Brazilian yellow scorpion Tityus stigmurus venom gland, an underexplored source for toxic peptides with possible biotechnological applications. Stigmurin was investigated in silico, by circular dichroism (CD) spectroscopy, and in vitro. The CD spectra suggested that this peptide interacts with membranes, changing its conformation in the presence of an amphipathic environment, with predominance of random coil and beta-sheet structures. Stigmurin exhibited antibacterial and antifungal activity, with minimal inhibitory concentrations ranging from 8.7 to 69.5µM. It was also showed that Stigmurin is toxic against SiHa and Vero E6 cell lines. The results suggest that Stigmurin can be considered a potential anti-infective drug.


Asunto(s)
Antibacterianos/farmacología , Péptidos Catiónicos Antimicrobianos/farmacología , Proteínas de Artrópodos/farmacología , Venenos de Escorpión/química , Escorpiones/química , Secuencia de Aminoácidos , Animales , Antibacterianos/química , Péptidos Catiónicos Antimicrobianos/química , Proteínas de Artrópodos/química , Secuencia de Bases , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Chlorocebus aethiops , Escherichia coli/efectos de los fármacos , Hemólisis , Humanos , Pruebas de Sensibilidad Microbiana , Modelos Moleculares , Datos de Secuencia Molecular , Estructura Secundaria de Proteína , Homología de Secuencia de Aminoácido , Staphylococcus aureus/efectos de los fármacos , Células Vero
10.
Int J Mol Sci ; 15(2): 2368-85, 2014 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-24518681

RESUMEN

In this study, we evaluated the effect of different doses of polysaccharides extracted from Caripia montagnei mushroom at different intervals of treatment on colonic injury in the model of colitis induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS). The FT-IR analysis and NMR showed that the polysaccharides from this species of mushroom are composed of α- and ß-glucans. The colonic damage was evaluated by macroscopic, histological, biochemical and immunologic analyses. The results showed the reduction of colonic lesions in all groups treated with the glucans. Such glucans significantly reduced the levels of IL-6 (50 and 75 mg/kg, p < 0.05), a major inflammatory cytokine. Biochemical analyses showed that the glucans from C. montagnei acted on reducing levels of alkaline phosphatase (75 mg/kg, p < 0.01) and myeloperoxidase (p < 0.001), a result confirmed by the reduction of cellular infiltration observed microscopically. The increase of catalase activity possibly indicates a protective effect of these glucans on colonic tissue, confirming their anti-inflammatory potential.


Asunto(s)
Agaricales/química , Colitis/patología , Glucanos/farmacología , Fosfatasa Alcalina/metabolismo , Animales , Catalasa/metabolismo , Colitis/inducido químicamente , Colitis/tratamiento farmacológico , Colitis/metabolismo , Citocinas/biosíntesis , Modelos Animales de Enfermedad , Activación Enzimática , Glucanos/administración & dosificación , Glucanos/química , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patología , Masculino , Óxido Nítrico , Resonancia Magnética Nuclear Biomolecular , Peroxidasa/metabolismo , Ratas , Espectroscopía Infrarroja por Transformada de Fourier , Ácido Trinitrobencenosulfónico/efectos adversos
11.
Int J Biochem Cell Biol ; 45(12): 2864-73, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24144578

RESUMEN

A new lectin from the marine sponge Haliclona caerulea (H-3) was isolated using a combination of hydrophobic interaction chromatography and ion-exchange chromatography. H-3 is a protein with three distinct bands on SDS-PAGE: 9 kDa, 16 kDa and 18 kDa. Nevertheless, on gel filtration and N-PAGE, H-3 showed a symmetrical peak and a unique band, respectively. Hemagglutinating activity of H-3 was stable at neutral pH and temperatures up to 60 °C. N-Acetylgalactosamine and porcine stomach mucin were the most potent inhibitors of H-3. Primary structure of the lectin was determined using tandem mass spectrometry, and it showed no similarity to any members of the animal lectin families. Top down fragmentation revealed some posttranslational modifications in H-3, including glycosylation. The glycan composition of H-3 was determined, and its structure was predicted. Furthermore, H-3 is a blue protein, binding to a chromophore(-597) by weak interactions, and this is the first time that the interaction between one lectin and a natural chromophore has been shown.


Asunto(s)
Haliclona/química , Lectinas/química , Animales , Cromatografía en Gel , Glicosilación , Lectinas/aislamiento & purificación , Lectinas/farmacología , Espectrometría de Masas/métodos
12.
Biochem Biophys Res Commun ; 430(1): 113-8, 2013 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-23200836

RESUMEN

Potassium channels are involved in the maintenance of resting membrane potential, control of cardiac and neuronal excitability, neurotransmitters release, muscle contractility and hormone secretion. The Tityus stigmurus scorpion is widely distributed in Northeastern Brazil and known to cause severe human envenomations, inducing pain, hypoesthesia, edema, erythema, paresthesia, headaches and vomiting. Most potassium channel blocking peptides that have been purified from scorpion venoms contain 30-40 amino acids with three or four disulfide bridges. These peptides belong to α-KTx subfamily. On the other hand, the ß-KTx subfamily is poorly characterized, though it is very representative in some scorpion venoms. A transcriptomic approach of T.stigmurus scorpions developed by our group revealed the repertoire of possible molecules present in the venom, including many toxins of the ß-KTx subfamily. One of the ESTs found, named TSTI0003C has a cDNA sequence of 538 bp codifying a mature protein with 47 amino acid residues, corresponding to 5299 Da. This ß-KTx peptide is a new member of the BmTXKß-related toxins, and was here named TstKMK. The three-dimensional structure of this potassium channel toxin of the T. stigmurus scorpion was obtained by computational modeling and refined by molecular dynamic simulations. Furthermore, we have made docking simulations using a Shaker kV-1.2 potassium channel from rats as receptor model and proposed which amino acid residues and interactions could be involved in its blockade.


Asunto(s)
Péptidos/química , Bloqueadores de los Canales de Potasio/química , Venenos de Escorpión/química , Escorpiones/química , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Clonación Molecular , ADN Complementario/genética , Modelos Químicos , Simulación de Dinámica Molecular , Datos de Secuencia Molecular , Péptidos/genética , Conformación Proteica , Venenos de Escorpión/genética , Escorpiones/genética
13.
Genet Mol Biol ; 34(2): 244-51, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21734825

RESUMEN

Chamaecrista belongs to subtribe Cassiinae (Caesalpinioideae), and it comprises over 330 species, divided into six sections. The section Xerocalyx has been subjected to a profound taxonomic shuffling over the years. Therefore, we conducted a phylogenetic analysis using a cpDNA trnE-trnT intergenic spacer and nrDNA ITS/5.8S sequences from Cassiinae taxa, in an attempt to elucidate the relationships within this section from Chamaecrista. The tree topology was congruent between the two data sets studied in which the monophyly of the genus Chamaecrista was strongly supported. Our analyses reinforce that new sectional boundaries must be defined in the Chamaecrista genus, especially the inclusion of sections Caliciopsis and Xerocalyx in sect. Chamaecrista, considered here paraphyletic. The section Xerocalyx was strongly supported as monophyletic; however, the current data did not show C. ramosa (microphyllous) and C. desvauxii (macrophyllous) and their respective varieties in distinct clades, suggesting that speciation events are still ongoing in these specimens.

14.
Genet. mol. biol ; 34(2): 244-251, 2011. ilus, tab
Artículo en Inglés | LILACS | ID: lil-587744

RESUMEN

Chamaecrista belongs to subtribe Cassiinae (Caesalpinioideae), and it comprises over 330 species, divided into six sections. The section Xerocalyx has been subjected to a profound taxonomic shuffling over the years. Therefore, we conducted a phylogenetic analysis using a cpDNA trnE-trnT intergenic spacer and nrDNA ITS/5.8S sequences from Cassiinae taxa, in an attempt to elucidate the relationships within this section from Chamaecrista. The tree topology was congruent between the two data sets studied in which the monophyly of the genus Chamaecrista was strongly supported. Our analyses reinforce that new sectional boundaries must be defined in the Chamaecrista genus, especially the inclusion of sections Caliciopsis and Xerocalyx in sect. Chamaecrista, considered here paraphyletic. The section Xerocalyx was strongly supported as monophyletic; however, the current data did not show C. ramosa (microphyllous) and C. desvauxii (macrophyllous) and their respective varieties in distinct clades, suggesting that speciation events are still ongoing in these specimens.

15.
J Plant Physiol ; 164(5): 591-600, 2007 May.
Artículo en Inglés | MEDLINE | ID: mdl-16690169

RESUMEN

In this study, we compare some antioxidative responses of leaves and roots associated to growth reduction in cowpea plants (Vigna unguiculata) during short-term salt stress and recovery. The salt treatment was imposed (200 mM NaCl) for six consecutive days and the salt withdrawal after 3 d. The salt treatment caused an almost complete cessation in the relative growth rate of both leaves and roots. Although NaCl withdrawal has induced an intense reduction in the Na(+) content from the leaves and roots, the growth recovery was slight, after 3 d. The leaf lipid peroxidation was increased in salt-stressed plants and slightly reduced in recovered plants after 3 d. Surprisingly, in the salt-stressed roots it decreased markedly after 3 d treatment and in the pre-stressed/recovered roots it was restored to levels near to the control. In leaves, catalase (CAT) activity showed a rapid and prominent decrease after 1 d of NaCl treatment and salt withdrawal had no effect on its recovery. In contrast, the root CAT activity was not changed by effects of both NaCl and salt withdrawal, over time interval. Leaf superoxide dismutase (SOD) activity did not change in all treatments, whereas in roots it significantly decreased after 3 d of salt treatment and recovered after NaCl withdrawal. Contrasting to the other enzymes, the guaiacol-peroxidase activity increased in leaves and roots, reaching almost 200% of control values and it significantly decreased in both organs from the pre-stressed/recovered plants. In conclusion, cowpea roots and leaves present distinct mechanisms of response to lipid peroxidation and CAT and SOD activities during salt stress and recovery. However, these responses and/or the oxidative damages caused by reactive oxygen species were not related with the growth reduction.


Asunto(s)
Fabaceae/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/metabolismo , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/metabolismo , Cloruro de Sodio/farmacología , Fabaceae/metabolismo , Hojas de la Planta/crecimiento & desarrollo , Raíces de Plantas/crecimiento & desarrollo , Factores de Tiempo
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