16 resultados para tobacco hairy roots
em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo
Resumo:
A phytochemical study of the ethyl acetate extract of the roots and adventitious roots of Spirotropis longifolia, a monodominant tree species of the Guianan rainforest, has allowed the isolation of three compounds: 2- hydroxy-8,9-methylenedioxy-2',2'-dimethylpyrano-[5',6':4,3]-6a-prenyl-[6aS,11aS]-pterocarpan (spirotropin A), 2-hydroxy-8,9-methylenedioxy-2',2'-dimethy1-3',4'-dihydropyrano-[5',6':4,3]-6a-prenyl-(6aS,11aS]-pterocarpan (spirotropin B), and 5,7-dihydroxy-6.8-dipreny1-2 ''''.2 ''''-dimethylpyrano[5 '''',6 '''': 3',4]-isoflavone (spirotropone). In addition, 10 known compounds, trans-oxyresveratrol, trans-resveratrol, piceatannol, daidzein, genistein, isoprunetin, lupeol, latifolol, gnetin D and gnetin E, were also isolated. These compounds were evaluated for their antifungal activity and their cytotoxicity, and their structures were established by 1D and 2D NMR, HRMS, CD and optical rotation measurements. (C) 2011 Elsevier Ltd. All rights reserved.
Resumo:
Background: Drought is a major abiotic stress that affects crop productivity worldwide. Sugarcane can withstand periods of water scarcity during the final stage of culm maturation, during which sucrose accumulation occurs. Meanwhile, prolonged periods of drought can cause severe plant losses. Methodology/Principal Findings: In a previous study, we evaluated the transcriptome of drought-stressed plants to better understand sugarcane responses to drought. Among the up-regulated genes was Scdr1 (sugarcane drought-responsive 1). The aim of the research reported here was to characterize this gene. Scdr1 encodes a putative protein containing 248 amino acids with a large number of proline (19%) and cysteine (13%) residues. Phylogenetic analysis showed that ScDR1is in a clade with homologs from other monocotyledonous plants, separate from those of dicotyledonous plants. The expression of Scdr1 in different varieties of sugarcane plants has not shown a clear association with drought tolerance. Conclusions/Significance: The overexpression of Scdr1 in transgenic tobacco plants increased their tolerance to drought, salinity and oxidative stress, as demonstrated by increased photosynthesis, water content, biomass, germination rate, chlorophyll content and reduced accumulation of ROS. Physiological parameters, such as transpiration rate (E), net photosynthesis (A), stomatal conductance (gs) and internal leaf CO2 concentration, were less affected by abiotic stresses in transgenic Scdr1 plants compared with wild-type plants. Overall, our results indicated that Scdr1 conferred tolerance to multiple abiotic stresses, highlighting the potential of this gene for biotechnological applications.
Resumo:
Auxyn type herbicides such as dicamba and 2,4-D are alternative herbicides that can be used to control glyphosate-resistant hairy fleabane. With the forthcoming possibility of releasing dicamba-resistant and 2,4-D-resistant crops, use of these growth regulator herbicides will likely be an alternative that can be applied to the control of glyphosate resistant hairy fleabane (Conyza bonariensis). The objective of this research was to model the efficacy, through dose-response curves, of glyphosate, 2,4-D, isolated dicamba and glyphosate-dicamba combinations to control a brazilian hairy fleabane population resistant to glyphosate. The greenhouse dose-response studies were conducted as a completely randomized experimental design, and the rates used for dose response curve construction were 0, 120, 240, 480, 720 and 960 ga.i. ha(-1) for 2,4-D, dicamba and the dicamba combination, with glyphosate at 540 g a. e. ha(-1). The rates for glyphosate alone were 0, 180, 360, 540, 720 and 960 g a. e. ha(-1). Herbicides were applied when the plants were in a vegetative stage with 10 to 12 leaves and height between 12 and 15 cm. Hairy fleabane had low sensitivity to glyphosate, with poor control even at the 960 g a. e. ha(-1) rate. Dicamba and 2,4-D were effective in controlling the studied hairy fleabane. Hairy fleabane responds differently to 2,4-D and dicamba. The combination of glyphosate and dicamba was not antagonistic to hairy fleabane control, and glyphosate may cause an additive effect on the control, despite the population resistance.
Resumo:
Thiamethoxam is a systemic insecticide from the neonicotinoid group, nitroguanidin family which affects the nicotinic receptor acetyl choline in the insect membrane, wounding the nervous system and causing the death of the insect. It was used with success in the control of initial pests of several crops. It was considered that thiamethoxam has a bioactivator effect, because in the absence of insects promoted increase in vigor, development and productivity of crops. This work was carried out to verify if thiamethoxam causes histological changes in sugarcane roots. In this work, it was used optical microscopy, images arrest, tissue biometrics and statistical analysis, in young roots of sugarcane RB 83 5486 after the treatments with different thiamethoxam concentrations. It was determined changes in histological structure of tissues 7, 14, 21 and 28 days after the treatments, establishing its effects on root plant anatomy. It was verified that thiamethoxam increased root cortex width, increasing the vascular cylinder and the metaxylem vessel elements number in the vascular tissue until 21 days after application.
Resumo:
We present a family of networks whose local interconnection topologies are generated by the root vectors of a semi-simple complex Lie algebra. Cartan classification theorem of those algebras ensures those families of interconnection topologies to be exhaustive. The global arrangement of the network is defined in terms of integer or half-integer weight lattices. The mesh or torus topologies that network millions of processing cores, such as those in the IBM BlueGene series, are the simplest member of that category. The symmetries of the root systems of an algebra, manifested by their Weyl group, lends great convenience for the design and analysis of hardware architecture, algorithms and programs.
Resumo:
The myelography procedure is reported in an adult of the Sphiggurus villosus (hairy-tree-porcupine) species coming from the wild, in the region of Curitiba/PR. After proceeding with the examination, while the animal was under general anesthesia, there was a dorsal deviation of the contrast in the height of the seventh thoracic vertebra (T-7) caused by compression in the ventral region of the vertebra. This is suggestive of edema caused by intramedullary hemorrhage secondary to trauma suffered by the animal in the wild. Therefore, the use of myelography in Sphiggurus villosus (hairy-tree-porcupine) proved to be quite valid and efficient, presenting the advantages of greater precision to delimit and locate the lesion present in the vertebral column.
Resumo:
Recent systematic reviews concluded that the frequent consumption of fruits and vegetables is inversely associated with the risk of oral cancer. We assessed this association, specifically comparing results obtained to nonsmokers and smokers, as well to nondrinkers and drinkers. We conducted a case-control study involving 296 patients with oral squamous cell carcinoma (cases) attended in 3 major hospitals of Sao Paulo, Brazil, paired with 296 controls, recruited from outpatient units of the same hospitals. Multivariate models assessed the effect of fruits and salads according to smoking and drinking. The intake of fruit was associated with the prevention of the disease in the specific assessment among light [odds ratio (OR) = 0.46; 95% confidence interval (CI) = 0.27-0.78) and heavy (OR = 0.30; 95% CI = 0.14-0.65) smokers. The same was observed for vegetables consumption. For nonsmokers, no fruit (OR = 50; 95% CI = 0.22-1.12) or vegetable (for tomato, OR = 0.53; 95% CI = 0.31-0.93) was associated with reduced risk of oral and oropharyngeal cancer. Similar results were found in the stratified analysis according to drinking status with OR = 0.51 (95% CI = 0.30-0.87) and 0.18 for fruits (95% CI = 0.07-0.45), respectively, for light and heavy drinkers. This observation suggests that the protective effect of fruit and salad intake may modulate the deleterious effects from tobacco and alcohol.
Resumo:
Background Tax policy is considered the most effective strategy to reduce tobacco consumption and prevalence. Tax avoidance and tax evasion therefore undermine the effectiveness of tax policies and result in less revenue for governments, cheaper prices for smokers and increased tobacco use. Tobacco smuggling and illicit tobacco trade have probably always existed, since tobacco's introduction as a valuable product from the New World, but the nature of the trade has changed. Methods This article clarifies definitions, reviews the key issues related to illicit trade, describes the different ways taxes are circumvented and looks at the size of the problem, its changing nature and its causes. The difficulties of data collection and research are discussed. Finally, we look at the policy options to combat illicit trade and the negotiations for a WHO Framework Convention on Tobacco Control (FCTC) protocol on illicit tobacco trade. Results Twenty years ago the main type of illicit trade was large-scale cigarette smuggling of well known cigarette brands. A change occurred as some major international tobacco companies in Europe and the Americas reviewed their export practices due to tax regulations, investigations and lawsuits by the authorities. Other types of illicit trade emerged such as illegal manufacturing, including counterfeiting and the emergence of new cigarette brands, produced in a rather open manner at well known locations, which are only or mainly intended for the illegal market of another country. Conclusions The global scope and multifaceted nature of the illicit tobacco trade requires a coordinated international response, so a strong protocol to the FCTC is essential. The illicit tobacco trade is a global problem which needs a global solution.
Resumo:
Environmental tobacco smoke (ETS) leads to the death of 600,000 nonsmokers annually and is associated with disturbances in antioxidant enzyme capacity in the adult rodent brain. However, little is known regarding the influence of ETS on brain development. The aim of this study was to determine levels of malonaldehyde (MDA) and 3-nitrotyrosine (3-NT), as well as enzymatic antioxidant activities of glutathione peroxidase (GPx), glutathione reductase (GR), glutathione S-transferase (GST), and superoxide dismutase (SOD), in distinct brain structures. BALB/c mice were exposed to ETS twice daily for 1 h from postnatal day 5 through postnatal day 18. Acute exposure was performed for 1 h on postnatal day 18. Mice were euthanized either immediately (0) or 3 h after the last exposure. Immediately after an acute exposure there were higher GR and GST activities and MDA levels in the hippocampus, higher GPx and SOD activities in the prefrontal cortex, and higher GST activity and MDA levels in the striatum and cerebellum. Three hours later there was an increase in SOD activity and MDA levels in the hippocampus and a decrease in the activity of all enzymes in the prefrontal cortex. Immediately after final repeated exposure there were elevated levels of GST and GR activity and decreased GPx activity in the hippocampus. Moreover, a rise was found in GPx and GST activities in the prefrontal cortex and increased GST and GPx activity in the striatum and cerebellum, respectively. After 3 h the prefrontal cortex showed elevated GR and GST activities, and the striatum displayed enhanced GST activity. Data showed that enzymatic antioxidant system in the central nervous system responds to ETS differently in different regions of the brain and that a form of adaptation occurs after several days of exposure.
Resumo:
Abscisic acid (ABA) is an important regulator of plant responses to environmental stresses and an absolute requirement for stress tolerance. Recently, a third phytoene synthase (PSY3) gene paralog was identified in monocots and demonstrated to play a specialized role in stress-induced ABA formation, thus suggesting that the first committed step in carotenogenesis is a key limiting step in ABA biosynthesis. To examine whether the ectopic expression of PSY, other than PSY3, would similarly affect ABA level and stress tolerance, we have produced transgenic tobacco containing a fruit-specific PSY (CpPSY) of grapefruit (Citrus paradisi Macf.). The transgenic plants contained a single- or double-locus insertion and expressed CpPSY at varying transcript levels. In comparison with the wild-type plants, the CpPSY expressing transgenic plants showed a significant increase on root length and shoot biomass under PEG-, NaCl- and mannitol-induced osmotic stress. The enhanced stress tolerance of transgenic plants was correlated with the increased endogenous ABA level and expression of stress-responsive genes, which in turn was correlated with the CpPSY copy number and expression level in different transgenic lines. Collectively, these results provide further evidence that PSY is a key enzyme regulating ABA biosynthesis and that the altered expression of other PSYs in transgenic plants may provide a similar function to that of the monocot's PSY3 in ABA biosynthesis and stress tolerance. The results also pave the way for further use of CpPSY, as well as other PSYs, as potential candidate genes for engineering tolerance to drought and salt stress in crop plants.
Resumo:
Many techniques have been proposed for root coverage. However, none of them presents predictable results in deep and wide recessions. Objective: The aim of this case series report is to describe an alternative technique for root coverage at sites showing deep recessions and attachment loss >4 mm at buccal sites. Material and Methods: Four patients presenting deep recession defects at buccal sites (>= 4 mm) were treated by the newly forming bone graft technique, which consists in the creation of an alveolar socket at edentulous ridge and transferring of granulation tissue present in this socket to the recession defect after 21 days. Clinical periodontal parameters, including recession depth (RD), probing depth (PD), clinical attachment level (CAL), bleeding on probing (BOP), plaque index (PI) and keratinized gingiva width (KGW) were evaluated by a single examiner immediately before surgery and at 1, 3, 6 and 9 months postoperatively. Results: All cases showed reduction in RD and PD, along with CAL gain, although no increase in KGW could be observed. These findings suggest that the technique could favor periodontal regeneration along with root coverage, especially in areas showing deep recessions and attachment loss.
Resumo:
Despite the wide use of plant regeneration for biotechnological purposes, the signals that allow cells to become competent to assume different fates remain largely unknown. Here, it is demonstrated that the Regeneration1 (Rg1) allele, a natural genetic variation from the tomato wild relative Solanum peruvianum, increases the capacity to form both roots and shoots in vitro; and that the gibberellin constitutive mutant procera (pro) presented the opposite phenotype, reducing organogenesis on either root-inducing medium (RIM) or shoot-inducing medium (SIM). Mutants showing alterations in the formation of specific organs in vitro were the auxin low-sensitivity diageotropica (dgt), the lateral suppresser (ls), and the KNOX-overexpressing Mouse ears (Me). dgt failed to form roots on RIM, Me increased shoot formation on SIM, and the high capacity for in vitro shoot formation of ls contrasted with its recalcitrance to form axillary meristems. Interestingly, Rg1 rescued the in vitro organ formation capacity in proRg1 and dgtRg1 double mutants and the ex vitro low lateral shoot formation in pro and ls. Such epistatic interactions were also confirmed in gene expression and histological analyses conducted in the single and double mutants. Although Me phenocopied the high shoot formation of Rg1 on SIM, it failed to increase rooting on RIM and to rescue the non-branching phenotype of ls. Taken together, these results suggest REGENERATION1 and the DELLA mutant PROCERA as controlling a common competence to assume distinct cell fates, rather than the specific induction of adventitious roots or shoots, which is controlled by DIAGEOTROPICA and MOUSE EARS, respectively.
Resumo:
In imaging diagnosis, redundant nerve roots of the cauda equina are characterized by the presence of elongated, enlarged and tortuous nerve roots in close relationship with a high-grade lumbar spinal canal stenosis. This is not an independent entity, but it is believed to be a consequence of the chronic compression at the level of the lumbar canal stenosis and thus may be part of the natural history of lumbar spinal stenosis. The present paper is aimed at reviewing the histopathological, electrophysiological and imaging findings, particularly at magnetic resonance imaging, as well as the clinical meaning of this entity. As the current assessment of canal stenosis and root compression is preferably performed by means of magnetic resonance imaging, this is the imaging method by which the condition is identified. The recognition of redundant nerve roots at magnetic resonance imaging is important, particularly to avoid misdiagnosing other conditions such as intradural arteriovenous malformations. The literature approaching the clinical relevance of the presence of redundant nerve roots is controversial. There are articles suggesting that the pathological changes of the nerve roots are irreversible at the moment of diagnosis and therefore neurological symptoms are less likely to improve with surgical decompression, but such concept is not a consensus.
Resumo:
Auxyn type herbicides such as dicamba and 2,4-D are alternative herbicides that can be used to control glyphosate-resistant hairy fleabane. With the forthcoming possibility of releasing dicamba-resistant and 2,4-D-resistant crops, use of these growth regulator herbicides will likely be an alternative that can be applied to the control of glyphosate resistant hairy fleabane (Conyza bonariensis). The objective of this research was to model the efficacy, through dose-response curves, of glyphosate, 2,4-D, isolated dicamba and glyphosatedicamba combinations to control a brazilian hairy fleabane population resistant to glyphosate. The greenhouse dose-response studies were conducted as a completely randomized experimental design, and the rates used for dose response curve construction were 0, 120, 240, 480, 720 and 960 g a.i. ha-1 for 2,4-D, dicamba and the dicamba combination, with glyphosate at 540 g a.e. ha-1. The rates for glyphosate alone were 0, 180, 360, 540, 720 and 960 g a.e. ha-1. Herbicides were applied when the plants were in a vegetative stage with 10 to 12 leaves and height between 12 and 15 cm. Hairy fleabane had low sensitivity to glyphosate, with poor control even at the 960 g a.e. ha-1 rate. Dicamba and 2,4-D were effective in controlling the studied hairy fleabane. Hairy fleabane responds differently to 2,4-D and dicamba. The combination of glyphosate and dicamba was not antagonistic to hairy fleabane control, and glyphosate may cause an additive effect on the control, despite the population resistance.
Resumo:
PURPOSE: Investigate the morphological effects of chronic exposure to tobacco smoke inhalation and alcohol consumption on the lungs and on the growth of rats. METHODS: Sixty male Wistar rats were divided into four groups: control, tobacco, alcohol, tobacco + alcohol, for a period of study 260 days. Morphological analysis was conducted by optical and electron microscopy. Rat growth was investigated by measuring the snout-anus length, body mass index and body weight. RESULTS: The three groups exposed to the drugs presented lower growth and lower weight than the control group. The percentages of alveolitis, bronchiolitis and the mean alveolar diameter were greater, particularly in the groups exposed to tobacco smoke, but were not significantly different from the control group. Electron microscopy revealed more intense apoptotic and degenerative lesions in the smoking group, while degenerative lesions in the lamellar bodies were more intense with the association of both drugs. CONCLUSIONS: This experimental model showed morphological alterations observed by electron microscopy, principally due to tobacco smoke exposure. Alcohol and tobacco hindered the growth of rats, such that tobacco showed a greater effect on body length and alcohol on body weight.