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1.
Environ Monit Assess ; 195(9): 1131, 2023 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-37653163

RESUMO

Green manure decomposition and nutrient recycling improve soil quality and productivity of different crops, but information on irrigated fruit orchards in the Brazilian semi-arid region is still scarce. Decomposition and nitrogen, phosphate, and potassium release from the cut biomass of three green manure legumes (sunn hemp, pigeon pea and jack bean) placed in litterbags, and spontaneous vegetation grown for 90 days in the rows of a passion fruit orchard were followed for 150 days. Biomasses decreased exponentially, reaching 12 (sunn hemp) to 25% (jack beans and spontaneous vegetation) after 150 days. K was rapidly released (< 21 and 4% of the original content remaining after 7 and 150 days, respectively), contrasting with more than half of the P and one third of the N remaining after 150 days. The amounts released were more influenced by the amounts of biomass produced (sunn hemp, 1583); (Jack bean 5152 kg ha-1); (Pigeon pea 822 kg ha-1); (Spontaneous plants 3175 kg ha-1); (spontaneous legumes 744 kg ha-1) than by variation in decomposition proportions among species. N release represented a liquid input to the soil, since more than 80% of the green manure and spontaneous vegetation contents came from N2-symbiotic fixation. Therefore, green manure is an effective technique to incorporate N and recycle K and P in irrigated orchards in the Brazilian semi-arid region.


Assuntos
Fabaceae , Passiflora , Biomassa , Brasil , Frutas , Esterco , Monitoramento Ambiental , Nutrientes , Solo , Verduras
3.
Environ Sci Pollut Res Int ; 30(26): 68271-68289, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37119494

RESUMO

Organic fertilization and mycorrhization can increase the phytoremediation of copper-contaminated soils. The time of vermicomposting alters the properties of vermicompost, which can affect copper's availability and uptake. Therefore, this study sought to evaluate the effect of different organic fertilizers and mycorrhization on copper-contaminated soil phytoremediation. The soil was contaminated with 100 mg Cu kg-1 dry soil and received mineral fertilizer (MIN), bovine manure (CM), and vermicompost produced in 45 days (V45) or 120 days (V120), all in doses equivalent to 40 mg kg-1 dry soil of phosphorus. Half of the jack bean (Canavalia ensiformis) plants were inoculated with the arbuscular mycorrhizal fungus Rhizophagus clarus. At plant flowering, the dry mass and concentrations of Cu, Zn, Mn, Ca, Mg, P, and K in the soil, solution, and plant tissue were determined, in addition to mycorrhizal colonization, nodulation, photosynthetic pigments, and oxidative stress enzyme activity. Organic fertilization increased plant growth and copper accumulation in aerial tissues. These effects were more evident with the V120, making it suitable for use in copper phytoextraction. Mycorrhization increased root and nodule dry mass, making it recommended for phytostabilization. C. ensiformis nodulation in Cu-contaminated soils depends on vermicompost fertilization and mycorrhization. Hence, the copper phytoremediation by C. ensiformis is increased by using organic fertilization and mycorrhization.


Assuntos
Micorrizas , Poluentes do Solo , Animais , Bovinos , Cobre/análise , Solo , Biodegradação Ambiental , Areia , Canavalia , Poluentes do Solo/análise , Fertilização
4.
Curr Pharm Des ; 29(10): 777-792, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36999428

RESUMO

Helicobacter pylori and Cryptococcus ssp. are pathogenic ureolytic microorganisms that cause several disorders in the host organism and, in severe cases, lead to death. Both infections have the urease enzyme as a key virulence factor since they use its ability to produce ammonia to soften the inhospitable pH to which they are subjected. In this review, we describe two ureases as possible molecular targets for drug discovery and provide insights for developing potent inhibitors against ureases from these pathogenic microorganisms through computer-aided drug discovery approaches, such as structure-based drug design (SBDD) and structure-activity relationship (SAR). The SAR studies have indicated several essential subunits and groups to be present in urease inhibitors that are critical for inhibitory activity against H. pylori or Cryptococcus spp. Since the threedimensional structure of C. neoformans urease has yet to be determined experimentally, the plant urease of Canavalia ensiformis was used in this study due to its structural similarity. Therefore, in the SBDD context, FTMap and FTSite analyses were performed to reveal characteristics of the urease active sites in two protein data bank files (4H9M, Canavalia ensiformis, and 6ZJA, H. pylori). Finally, a docking-based analysis was performed to explore the best inhibitors described in the literature to understand the role of the ligand interactions with the key residues in complex ligand-urease stabilization, which can be applied in the design of novel bioactive compounds.


Assuntos
Cryptococcus neoformans , Helicobacter pylori , Humanos , Urease/química , Urease/metabolismo , Cryptococcus neoformans/metabolismo , Ligantes , Canavalia/metabolismo
5.
Regen Ther ; 22: 68-78, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36712959

RESUMO

Heart failure is caused by various factors, making the underlying pathogenic mechanisms difficult to identify. Since cardiovascular disease tends to worsen over time, early diagnosis is key for treatment. In addition, understanding the qualitative changes in the heart associated with aging, where information on the direct influences of aging on cardiovascular disease is limited, would also be useful for treatment and diagnosis. To fill these research gaps, the focus of our study was to detect the structural and functional molecular changes associated with the heart over time, with a focus on glycans, which reflect the type and state of cells. METHODS: We investigated glycan localization in the cardiac tissue of normal mice and their alterations during aging, using evanescent-field fluorescence-assisted lectin microarray, a technique based on lectin-glycan interaction, and lectin staining. RESULTS: The glycan profiles in the left ventricle showed differences between the luminal side (medial) and wall side (lateral) regions. The medial region was characterized by the presence of sialic acid residues. Moreover, age-related changes in glycan profiles were observed at a younger age in the medial region. The difference in the age-related decrease in the level of α-galactose stained with Griffonia simplicifolia lectin-IB4 in different regions of the left ventricle suggests spatiotemporal changes in the number of microvessels. CONCLUSIONS: The glycan profile, which retains diverse glycan structures, is supported by many cell populations, and maintains cardiac function. With further research, glycan localization and changes have the potential to be developed as a marker of the signs of heart failure.

6.
Int J Biol Macromol ; 222(Pt B): 2823-2832, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36228819

RESUMO

Mannose/glucose-binding lectin from Canavalia ensiformis seeds (Concanavalin A - ConA) has several biological applications, such as mitogenic and antitumor activity. However, most of the mechanisms involved in the in vivo toxicity of ConA are not well known. In this study, the Drosophila melanogaster model was used to assess the toxicity and genotoxicity of different concentrations of native ConA (4.4, 17.5 and 70 µg/mL) in inhibited and denatured forms of ConA. The data show that native ConA affected: the survival, in the order of 30.6 %, and the locomotor performance of the flies; reduced cell viability to levels below 50 % (4.4 and 17.5 µg/mL); reduced nitric oxide levels; caused lipid peroxidation and increased protein and non-protein thiol content. In the Comet assay, native ConA (17.5 e 70 µg/mL) caused DNA damage higher than 50 %. In contrast, treatments with inhibited and denatured ConA did not affect oxidative stress markers and did not cause DNA damage. We believe that protein-carbohydrate interactions between ConA and carbohydrates of the plasma membrane are probably the major events involved in these activities, suggesting that native ConA activates mechanisms that induce oxidative stress and consequently DNA damage.


Assuntos
Canavalia , Drosophila melanogaster , Animais , Canavalia/química , Drosophila melanogaster/metabolismo , Concanavalina A/química , Dano ao DNA , Estresse Oxidativo
7.
J Venom Res ; 10: 38-44, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33209252

RESUMO

Ureases are metalloenzymes that hydrolyze urea to ammonia and carbamate. The main urease isoforms present in the seeds of Canavalia ensiformis (jack bean urease - JBU and canatoxin) exert a variety of biological activities. The insecticidal activity of JBU is mediated, at least in part, by jaburetox (Jbtx), a recombinant peptide derived from the JBU amino acid sequence. In this article, we review the neurotoxicity of Jbtx in insects. The insecticidal activity of Jbtx has been investigated in a variety of insect orders and species, including Blattodea (the cockroaches Blatella germânica, Nauphoeta cinerea, Periplaneta americana e Phoetalia pallida), Bruchidae (Callosobruchus maculatus - cowpea weevil), Diptera (Aedes aegypti - mosquito), Hemiptera (Dysdercus peruvianus - cotton stainer bug; Oncopeltus fasciatus - large milkweed bug, and the kissing bugs Rhodnius prolixus and Triatoma infestans), Lepidoptera (Spodoptera frugiperda - fall army worm) and Orthoptera (Locusta migratoria - locust). In N. cinerea, the injection of Jbtx induces marked alteration of locomotor and grooming behavior, whereas in T. infestans Jbtx causes leg paralysis, an extension of the proboscis and abnormal antennal movements. Electromyographical analysis showed that Jbtx causes complete neuromuscular blockade in P. pallida. The same treatment in N. cinerea and L. migratoria causes a decrease in the action potential firing rate. Jbtx forms membrane pore-channels compatible with cations in bilipid membranes. A study using B. germanica voltage-gated sodium (Nav1.1) channels that were heterologously expressed in Xenopus laevis oocytes correlated the entomotoxicity of Jbtx with the activation of these channels. Taken together, these findings demonstrate the potential of this peptide as a natural pesticide.

8.
Molecules ; 25(11)2020 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-32471071

RESUMO

Although the intake of jack bean (Canavalia ensiformis (L.) DC.), an underutilized tropical legume, can potentially decrease the risk of several chronic diseases, not much effort has been directed at profiling the polyphenolics contained therein. Hence, this work aimed to identify and quantify the dominant jack bean polyphenolics, which are believed to have antioxidant and other bioactivities. Four major compounds were detected and identified as kaempferol glycosides with three or four glycoside units. Their structures were established based on UV-visible, 1d, 2D NMR, and HR-ESI-MS analyses. Specifically, kaempferol 3-O-a-l-rhamnopyranosyl (1®6)- b-d-glucopyranosyl (1®2)-b-d-galactopyranosyl-7-O-[3-O-o-anisoyl]-a-l-rhamnopyranoside was detected for the first time, while the other three compounds have already been described in plants other than jack bean. This new compound was found to have a higher a-glucosidase inhibition activity compared to acarbose.


Assuntos
Canavalia/química , Glucosidases/antagonistas & inibidores , Glicosídeos/química , Flavonóis/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Espectrometria de Massas por Ionização por Electrospray
9.
Artigo em Inglês | MEDLINE | ID: mdl-31812006

RESUMO

Concanavalin A is a representative of the plant protein group known as lectins. Many lectin proteins have useful characteristics for studies on cell division and cell surfaces. In this study, a new adsorbent for the specific separation of Concanavalin A was prepared by applying a silica particle surface imprinting method. First, silica particles were activated via acidic treatment, and then, 3-methacryloyloxypropyl trimethoxysilane (MPTMS) was used for modification. For the preparation of Concanavalin A surface-imprinted silica particles (Con A-MISPs), N-methacryloyl-l-histidine methyl ester (MAH) was used as a functional monomer. The silica particles were characterized using a Zetasizer, scanning electron microscopy equipment (SEM), and Fourier transform infrared spectroscopy (FTIR). The effects of parameters such as the pH, initial concentration of Concanavalin A, and temperature on the adsorption of Concanavalin A were determined. The maximum Concanavalin A adsorption onto Con A-MISPs was observed to be 305.2 mg/g at a pH of 6. The reusability of the Con A-MISPs was approximately 93.5%. The non-imprinted silica particles (NISPs) were prepared in the same manner without Concanavalin A to compare the surface imprinting factor. Selective binding studies were carried out with lysozyme and hemoglobin molecules. The selectivity of the Con A-MISPs was also investigated by isolating Concanavalin A from Canavalia ensiformis. The purity of the Concanavalin A was shown by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE).


Assuntos
Canavalia/química , Concanavalina A/isolamento & purificação , Impressão Molecular/métodos , Dióxido de Silício/química , Eletroforese em Gel de Poliacrilamida , Concentração de Íons de Hidrogênio , Temperatura
10.
J Adv Res ; 13: 113-126, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30094086

RESUMO

Schiff bases, an aldehyde- or ketone-like compounds in which the carbonyl group is replaced by an imine or azomethine, are some of the most widely used organic compounds. Indeed, they are widely used for industrial purposes and also exhibit a broad range of biological activities, including anti-urease activity. Ureases, enzymes that catalyze urea hydrolysis, have received considerable attention for their impact on living organisms' health, since the persistence of urease activity in human and animal cells can be the cause of some diseases and pathogen infections. This short review compiles examples of the most antiurease Schiff bases (0.23 µM < IC50 < 37.00 µM) and their metal complexes (0.03 µM < IC50 < 100 µM). Emphasis is given to ureases of Helicobacter pylori and Canavalia ensiformis, although the active site of this class of hydrolases is conserved among living organisms.

11.
Front Plant Sci ; 9: 613, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29780402

RESUMO

An understanding of the interaction between rice and dark septate endophytic (DSE) fungi, under green fertilization, may lead to sustainable agricultural practices. Nevertheless, this interaction is still poorly understood. Therefore, in this study, we aimed to evaluate the accumulation of macro- and micronutrients, dry matter, and protein and N recovery efficiency from Canavalia ensiformis (L.)-15N in rice inoculated with DSE fungi. An experiment under greenhouse conditions was conducted in a randomized complete block design comprising split-plots, with five replicates of rice plants potted in non-sterilized soil. Rice (Piauí variety) seedlings were inoculated with DSE fungi, A101 and A103, or left uninoculated (control) and transplanted into pots containing 12 kg of soil, which had previously been supplemented with dry, finely ground shoot biomass of C. ensiformis enriched with 2.15 atom % 15N. Two collections were performed in the experiment: one at 54 days after transplanting (DAT) and one at 130 DAT (at maturation). Growth indicators (at 54 DAT), grain yield, nutrient content, recovery efficiency, and the amount of N derived from C. ensiformis were quantified. At 54 DAT, the N content, chlorophyll content, and plant height of inoculated plants had increased significantly compared with the control, and these plants were more proficient in the use of N derived from C. ensiformis. At maturation, plants inoculated with A103 were distinguished by the recovery efficiency and amount of N derived from C. ensiformis and N content in the grain and shoot being equal to that in A101 inoculation and higher than that in the control, resulting in a higher accumulation of crude protein and dry matter in the full grain and panicle of DSE-rice interaction. In addition, Fe and Ni contents in the grains of rice inoculated with these fungi doubled with respect to the control, and in A103 inoculation, we observed Mn accumulation that was three times higher than in the other treatments. Our results suggest that the inoculation of rice with DSE fungi represents a strategy to improve green manure-N recovery, grain yield per plant, and grain quality in terms of micronutrients contents in cropping systems with a low N input.

12.
Front Chem ; 5: 58, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28824906

RESUMO

Peptic ulceration is among the most prevalent gastrointestinal disorders characterized by pepsin and gastric acid mediated mucosal damage, as result of imbalance between defensive and offensive processes. The main objective of the current study was to investigate the antiulcer potentials of Polygonum hydropiper crude methanolic ectract (Ph.Cr) in aspirin induced ulcerogenesis using pylorus ligated rat model. In-vitro urease and Proteus mirabilis inhibitory potentials were evaluated using standard protocols. All fractions were analyzed using GC-MS to identify major components. The aspirin induced ulcerogenesis in pylorus ligated rat model was associated with significant changes in the mean ulcer score [F(5, 30) = 7.141, P = 0.0002], gastric juice volume [F(5, 30) = 8.245, P < 0.0001], gastric juice pH [F(5, 30) = 5.715, P = 0.0008], free acidity [F(5, 30) = 4.544, P = 0.0033], total acidity [F(5, 30) = 2.740, P = 0.0373], and pepsin concentration [F(5, 30) = 2.335, P = 0.0664]. Pre-treatment with Ph.Cr at 100, 200, and 400 mg/kg dose exhibited marked gastroprotective and anti-ulcerogenic effect in the aspirin induced pyloric ligation ulcerogenesis model at 100, 200, and 400 mg/kg as indicated by ulcerative biochemical parameters. In urease inhibition assay, leaves essential oil (Ph.Lo), saponins (Ph.Sp), and chloroform extract (Ph.Chf) exhibited highest activities with IC50 of 90, 98, and 520 µg/ml, respectively. Ph.Sp, Ph.Chf, ethyl acetate (Ph.EtAc), and Ph.Cr showed MICs of 25, 30, 32.25, and 40.50 µg/ml, respectively against P. mirabilis. Several compounds were identified in GC-MS analysis of samples. Significant in-vivo antiulcer, urease inhibitory as well as anti-proteus potentials of P. hydropiper solvent extracts, signify its potential use for the management of peptic ulcers and may provide scientific bases for the traditional uses of the plant.

13.
Front Microbiol ; 8: 2437, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29312163

RESUMO

Dark septate endophytic (DSE) fungi are facultative biotrophs that associate with hundreds of plant species, contributing to their growth. These fungi may therefore aid in the search for sustainable agricultural practices. However, several ecological functions of DSE fungi need further clarification. The present study investigated the effects of DSE fungi inoculation on nutrient recovery efficiency, nutrient accumulation, and growth of tomato plants fertilized with organic and inorganic N sources. Two experiments were carried out under greenhouse conditions in a randomized blocks design, with five replicates of tomato seedlings grown in pots filled with non-sterile sandy soil. Tomato seedlings (cv. Santa Clara I-5300) inoculated with DSE fungi (isolates A101, A104, and A105) and without DSE fungi (control) were transplanted to pots filled with 12 kg of soil which had previously received finely ground plant material [Canavalia ensiformis (L.)] that was shoot enriched with 0.7 atom % 15N (organic N source experiment) or ammonium sulfate-15N enriched with 1 atom % 15N (mineral N source experiment). Growth indicators, nutrient content, amount of nitrogen (N) in the plant derived from ammonium sulfate-15N or C. ensiformis-15N, and recovery efficiency of 15N, P, and K by plants were quantified 50 days after transplanting. The treatment inoculated with DSE fungi and supplied with an organic N source showed significantly higher recovery efficiency of 15N, P, and K. In addition, the 15N, N, P, K, Ca, Mg, Fe, Mn, and Zn content, plant height, leaf number, leaf area (only for the A104 inoculation), and shoot dry matter increased. In contrast, the only positive effects observed in the presence of an inorganic N source were fertilizer-K recovery efficiency, content of K, and leaf area when inoculated with the fungus A104. Inoculation with A101, A104, and A105 promoted the growth of tomato using organic N source (finely ground C. ensiformis-15N plant material).

14.
Toxicon ; 110: 90-109, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26690979

RESUMO

Ureases are metalloenzymes that hydrolyze urea into ammonia and carbon dioxide. They were the first enzymes to be crystallized and, with them, the notion that enzymes are proteins became accepted. Novel toxic properties of ureases that are independent of their enzyme activity have been discovered in the last three decades. Since our first description of the neurotoxic properties of canatoxin, an isoform of the jack bean urease, which appeared in Toxicon in 1981, about one hundred articles have been published on "new" properties of plant and microbial ureases. Here we review the present knowledge on the non-enzymatic properties of ureases. Plant ureases and microbial ureases are fungitoxic to filamentous fungi and yeasts by a mechanism involving fungal membrane permeabilization. Plant and at least some bacterial ureases have potent insecticidal effects. This entomotoxicity relies partly on an internal peptide released upon proteolysis of ingested urease by insect digestive enzymes. The intact protein and its derived peptide(s) are neurotoxic to insects and affect a number of other physiological functions, such as diuresis, muscle contraction and immunity. In mammal models some ureases are acutely neurotoxic upon injection, at least partially by enzyme-independent effects. For a long time bacterial ureases have been recognized as important virulence factors of diseases by urease-producing microorganisms. Ureases activate exocytosis in different mammalian cells recruiting eicosanoids and Ca(2+)-dependent pathways, even when their ureolytic activity is blocked by an irreversible inhibitor. Ureases are chemotactic factors recognized by neutrophils (and some bacteria), activating them and also platelets into a pro-inflammatory "status". Secretion-induction by ureases may play a role in fungal and bacterial diseases in humans and other animals. The now recognized "moonlighting" properties of these proteins have renewed interest in ureases for their biotechnological potential to improve plant defense against pests and as potential targets to ameliorate diseases due to pathogenic urease-producing microorganisms.


Assuntos
Metaloproteínas/toxicidade , Neurotoxinas/toxicidade , Urease/toxicidade , Animais , Apoenzimas/genética , Apoenzimas/metabolismo , Apoenzimas/farmacologia , Apoenzimas/toxicidade , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/farmacologia , Proteínas de Bactérias/toxicidade , Fungicidas Industriais/farmacologia , Fungicidas Industriais/toxicidade , Humanos , Inseticidas/metabolismo , Inseticidas/farmacologia , Inseticidas/toxicidade , Isoenzimas/genética , Isoenzimas/metabolismo , Isoenzimas/farmacologia , Isoenzimas/toxicidade , Metaloproteínas/genética , Metaloproteínas/metabolismo , Metaloproteínas/farmacologia , Neurotoxinas/genética , Neurotoxinas/metabolismo , Neurotoxinas/farmacologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteínas de Plantas/farmacologia , Proteínas de Plantas/toxicidade , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/farmacologia , Proteínas Recombinantes/toxicidade , Urease/genética , Urease/metabolismo , Urease/farmacologia
15.
Biosci. j. (Online) ; 31(6): 1651-1662, nov./dec. 2015.
Artigo em Inglês | LILACS | ID: biblio-965115

RESUMO

Leaf area estimation models based on linear leaf dimensions are an important method because their application is not destructive to the leaves. For these models to be reliable, it is important that the estimation of model parameters is accurate, and for that to occur, the models must be generated using an adequate sample size (number of leaves). The objective of this study was to determine the number of leaves necessary to accurately model the leaf area of jack beans (Y), determined by digital photos, according to the width of the central leaflet (x), by a power model (Y = axb) generated through an iterative process. Accordingly, an experiment was performed in a 256 m2 area. A total of 745 leaves were randomly collected at six different crop development stages (29, 43, 57, 73, 87 and 101 days after emergence). Each leaf was comprised of a left, central and right leaflet. The width of the central leaflet (x) was measured on the 745 leaves. Leaf area (sum of the area of the left, central and right leaflets; Y) was then determined using a digital photo method. The number of leaves necessary for the estimation of the parameters a and b and the coefficient of determination (R2) of the power model were determined through resampling with replacement. The power model (Y = 4.2049x1.8215, R2 = 0.9701), based on the width of the central leaflet was determined to be adequate for estimating jack bean leaf area. Data collected from a sample of 200 leaves were determined to be sufficient for constructing an accurate power model for the leaf area of jack beans (Y) as a function of the width of the central leaflet (x), based on determinations of leaf area using digital photos.


Modelos de estimação de área foliar de plantas em função das dimensões lineares das folhas são importantes, principalmente, por não haver necessidade de destruição das folhas. Para modelos fidedignos, é importante que as estimativas de seus parâmetros sejam precisas, e, para isso, devem ser gerados a partir de um número adequado de folhas. O objetivo deste trabalho foi determinar o número de folhas necessário para modelar a área foliar de feijão de porco determinada por fotos digitais (Y) em função da largura do limbo do folíolo central da folha (x), por meio do modelo potência (Y = axb) gerado por processo iterativo. Para isso foi conduzido um experimento numa área de 256 m2, no qual, em seis períodos de desenvolvimento da cultura (29, 43, 57, 73, 87 e 101 dias após a emergência) foram coletadas, aleatoriamente, o total de 745 folhas. Cada folha é composta pelos folíolos esquerdo, central e direito. Nas 745 folhas foi mensurada a largura do limbo do folíolo central (x). A seguir, determinou-se a área foliar (soma da área dos folíolos esquerdo, central e direito) por meio do método de fotos digitais (Y). O número de folhas, necessário para a estimação dos parâmetros a e b do modelo potência e do coeficiente de determinação do modelo (R2), foi determinado por reamostragens, com reposição. Em feijão de porco, o modelo potência (Y = 4,2049x1,8215, R2 = 0,9701) da largura do limbo do folíolo central é adequado para estimar a área foliar obtida por fotos digitais. Mensurar 200 folhas é suficiente para construir modelos precisos do tipo potência, da área foliar de feijão de porco determinada por fotos digitais (Y) em função da largura do limbo do folíolo central da folha (x).


Assuntos
Tamanho da Amostra , Folhas de Planta , Canavalia
16.
Ann Bot ; 116(2): 149-87, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26205177

RESUMO

BACKGROUND: Observation of the diurnal ascent and descent of leaves of beans and other species, as well as experimental interventions into these movements, such as exposures to light at different times during the movement cycle, led to the concept of an endogenous 'clock' as a regulator of these oscillations. The physiological basis of leaf movement can be traced to processes that modulate cell volume in target tissues of the pulvinus and petiole. However, these elements of the leaf-movement process do not completely account for the rhythms that are generated following germination in constant light or dark conditions, or when plants are transferred to similar free-running conditions. SCOPE: To develop a new perspective on the regulation of leaf-movement rhythms, many of the published time courses of leaf movements that provided evidence for the concept of the endogenous clock were analysed in conjunction with the contemporaneous time courses of the lunisolar tidal acceleration at the relevant experimental locations. This was made possible by application of the Etide program, which estimates, with high temporal resolution, local gravitational changes as a consequence of the diurnal variations of the lunisolar gravitational force due to the orbits and relative positions of Earth, Moon and Sun. In all cases, it was evident that a synchronism exists between the times of the turning points of both the lunisolar tide and of the leaftide when the direction of leaf movement changes. This finding of synchrony leads to the hypothesis that the lunisolar tide is a regulator of the leaftide, and that the rhythm of leaf movement is not necessarily of endogenous origin but is an expression of an exogenous lunisolar 'clock' impressed upon the leaf-movement apparatus. CONCLUSIONS: Correlation between leaftide and Etide time courses holds for leaf movement rhythms in natural conditions of the greenhouse, in conditions of constant light or dark, under microgravity conditions of the International Space Station, and also holds for rhythms that are atypical, such as pendulum and relaxation rhythms whose periods are longer or shorter than usual. Even the apparently spontaneous short-period, small-amplitude rhythms recorded from leaves under unusual growth conditions are consistent with the hypothesis of a lunisolar zeitgeber. Two hypotheses that could account for the synchronism between leaftide and Etide, and which are based on either quantum considerations or on classical Newtonian physics, are presented and discussed.


Assuntos
Fabaceae/fisiologia , Gravitação , Lua , Movimento , Folhas de Planta/fisiologia , Sistema Solar , Ritmo Circadiano , Quimografia , Fatores de Tempo , Movimentos da Água
17.
Artigo em Inglês | MEDLINE | ID: mdl-26102634

RESUMO

Herein, an aptamer-based affinity chromatography method for rapid and single step purification of Concanavalin A is developed and validated. We have used a 41ntssDNA aptamer of Con A (Con A aptabody) as an affinity reagent in the developed aptamer-affinity chromatography. Stationary phase of the method consists of surface functionalized agarose beads carrying covalently immobilized Con A-aptabody. Affinity purification of Con A from jack bean (Canavalia ensiformis) seed using developed aptamer-affinity columns has resulted in ≥66% recovery with 90% purity and 336-fold purification of Con A. The developed aptamer-affinity chromatography has shown efficient scalability and consistent purification when analysed over 13mm, 20mm and 25mm diameter columns having a bed height of 60mm each. Also, the developed aptamer-agarose columns were found to be reusable with recovery decrease of 12.9% in seven sequential cycles of purification. Therefore, the developed aptamer-affinity chromatography provides a novel, efficient and single-step methodology for isolation and purification of Con A.


Assuntos
Aptâmeros de Nucleotídeos/química , Canavalia/química , Cromatografia de Afinidade/métodos , Concanavalina A/isolamento & purificação , Aptâmeros de Nucleotídeos/metabolismo , Concanavalina A/química , Concanavalina A/metabolismo , Cloreto de Sódio
18.
J Adv Res ; 6(1): 35-44, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25685542

RESUMO

Ureases, enzymes that catalyze urea hydrolysis, have received considerable attention for their impact on living organisms' health and life quality. On the one hand, the persistence of urease activity in human and animal cells can be the cause of some diseases and pathogen infections. On the other hand, food production can be negatively affected by ureases of soil microbiota that, in turn, lead to losses of nitrogenous nutrients in fields supplemented with urea as fertilizer. In this context, nature has proven to be a rich resource of natural products bearing a variety of scaffolds that decrease the ureolytic activity of ureases from different organisms. Therefore, this work compiles the state-of-the-art researches focused on the potential of plant natural products (present in extracts or as pure compounds) as urease inhibitors of clinical and/or agricultural interests. Emphasis is given to ureases of Helicobacter pylori, Canavalia ensiformis and soil microbiota although the active site of this class of hydrolases is conserved among living organisms.

19.
FEBS J ; 282(6): 1043-64, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25605001

RESUMO

Jaburetox is a polypeptide derived from jack bean (Canavalia ensiformis) urease and toxic to a broad spectrum of insects, phytopathogenic filamentous fungi and yeasts of medical importance. The elucidation of the structural basis for the mode of action of Jaburetox is the focus of this multifaceted study. Jaburetox in solution is a monomer of 11.0 kDa featuring a large hydrodynamic radius, suggestive of a disordered polypeptide. The intrinsically disordered nature of Jaburetox was theoretically predicted by a comprehensive bioinformatics analysis and experimentally confirmed by light scattering as well as by circular dichroism and NMR spectroscopy. NMR signal assignment provided backbone secondary chemical shifts that indicated that Jaburetox has a low propensity to assume a stable secondary structure. (15)N relaxation studies revealed significant backbone mobility, especially in the N-terminal portion of the polypeptide. The solution structure of Jaburetox shows the presence of an α-helical motif close to the N terminus, together with two turn-like structures situated in the central portion of the protein and close to the C terminus. Similar regions were predicted as potential protein-protein interaction sites using computational tools. The knowledge of the structural properties of Jaburetox in solution is a key step to correlate its structural and biological activities.


Assuntos
Antifúngicos/química , Inseticidas/química , Urease/química , Motivos de Aminoácidos , Animais , Canavalia/enzimologia , Dicroísmo Circular , Escherichia coli/metabolismo , Fluorometria , Hidrodinâmica , Insetos , Espectroscopia de Ressonância Magnética , Peptídeos/química , Proteínas de Plantas , Ligação Proteica , Estrutura Terciária de Proteína , Temperatura
20.
Int J Phytoremediation ; 17(1-6): 298-303, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25397989

RESUMO

Among the technologies used to recuperate cadmium (Cd) contaminated soils, phytoextraction are particularly important, where the selection of suitable plants is critical to the success of the soil remediation. Thus, the objectives of this study were to evaluate the responses of jack-bean and sorghum to Cd supply and to quantify Cd accumulation by these species grown in hydroponic culture. The plants were subjected to 0, 15, 30, or 60 µmol Cd L(-1) in the nutrient solution, and gas exchange, plant growth and Cd accumulation were measured at 25 days after starting Cd treatments. The Cd supply severely reduced growth of shoots and roots in both species. In jack-bean, Cd decreased photosynthesis by 56-86%, stomatal conductance by 59-85% and transpiration by 48-80%. The concentrations and amounts of Cd accumulated in the plant tissues were proportional to the metal supply in the nutrient solution. Sorghum was more tolerant than jack-bean to Cd toxicity, but the latter showed a greater metal concentration and accumulation in the shoot. Therefore, jack-bean would be more suitable than sorghum for use in Cd phytoremediation programs based on phytoextraction.


Assuntos
Cádmio/metabolismo , Canavalia/metabolismo , Recuperação e Remediação Ambiental/métodos , Sorghum/metabolismo , Biodegradação Ambiental , Cádmio/análise , Canavalia/química , Recuperação e Remediação Ambiental/instrumentação , Hidroponia , Sorghum/química
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