Letteratura scientifica selezionata sul tema "Plantar callus"
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Articoli di riviste sul tema "Plantar callus"
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Potter, J., e M. Potter. "Regrowth patterns of plantar callus". Foot 10, n. 3 (settembre 2000): 144–48. http://dx.doi.org/10.1054/foot.2000.0599.
Testo completo
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Duffin, Anthony C., Robert Kidd, Albert Chan e Kim C. Donaghue. "High Plantar Pressure and Callus in Diabetic Adolescents". Journal of the American Podiatric Medical Association 93, n. 3 (1 maggio 2003): 214–20. http://dx.doi.org/10.7547/87507315-93-3-214.
Testo completoAbstract (sommario):
This study examined the incidence of high peak plantar pressure and plantar callus in 211 adolescents with diabetes mellitus and 57 nondiabetic controls. The percentage of subjects with these anomalies was the same in both groups. Although diabetic subjects were no more likely than nondiabetic controls to have high peak plantar pressure and callus, these anomalies place individuals with diabetes at greater risk of future foot problems. The effects of orthoses, cushioning, and both in combination were monitored in 17 diabetic subjects with high peak plantar pressure and in 17 diabetic subjects with plantar callus; reductions of up to 63% were achieved. Twelve-month follow-up of diabetic subjects fitted with orthoses showed a significant reduction in peak plantar pressure even when the orthoses were removed. The diabetic subjects who had not received any interventions during the same 12-month period showed no significant change in peak plantar pressure. (J Am Podiatr Med Assoc 93(3): 214-220, 2003)
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Nasyaruddin Herry Taufik, Angela Bibiana Maria Tulaar, Nazar Moesbar e Ratna Akbarie Ganie. "The Effect of Isometric Exercise Plantar Flexor on Osteoblast Activity Measured by Bone Specific Alkaline Phosphatase and Callus Formation in a Patient Post Open Reduction Internal Fixation with Non-articular Tibia Fracture". Open Access Macedonian Journal of Medical Sciences 7, n. 20 (14 ottobre 2019): 3409–15. http://dx.doi.org/10.3889/oamjms.2019.435.
Testo completoAbstract (sommario):
BACKGROUND: Post-operative non-articular tibia fracture several problems that can occur include; pain, muscles atrophy, muscles weakness, joint stiffness, delayed union, and non-union that makes patients limited in their daily activities. Several factors that play a role in the process of fracture healing include osteoblast activity and exercise. Isometric exercises plantar flexor might effectively prevent the problem. Markers of osteoblast activity are bone-specific alkaline phosphatase (BSAP) levels and Hummer scale callus formation. Not yet known the effect isometric exercise of plantar flexor on osteoblast activity in the post open reduction internal fixation of non-articular tibia fractures, due to the lack of studies in this field.
AIM: This research was conducted to investigate the effect of isometric plantar flexor on osteoblast activity and callus formation in patients post open reduction internal fixation nonarticular tibial fractures.
HYPOTHESIS: There are differences in osteoblast activity and callus formation between groups that do isometric exercises of plantar flexor muscles with those that without isometric exercises plantar flexor.
ANALYSIS: Hypothesis test used a paired t-test with a value of α 0.05 and a confidence level of 95%.
METHODS: This clinical trial was true experimental with pre-post test control group design divided into two groups, group I obtained treatment of isometric exercises of the plantar flexor muscle, range of motion knee joint, and ankle while group II obtained the range of motion knee joints and ankle. Osteoblast activity measured with bone-specific alkaline phosphatase level and callus formation.
RESULTS: The result of the study found to increase mean bone-specific alkaline phosphatase group I; 15.6 and group II; 5.2. A paired t-test of independent samples with α of 0.05 and confidence interval 95% was obtained p-value = 0.000, there is a significant difference in increased levels of bone-specific alkaline phosphatase group I obtained isometric exercises plantar flexor with group II without isometric exercises plantar flexor in patients post open reduction internal fixation of a non-articular tibia fracture. Radiographic examination of Hummer scale callus in group I who carried out isometric exercises plantar flexor had an average value of 2.63, whereas group II without isometric exercises plantar flexor average of 3.06. Wilcoxon test with a 0.05 and 95% confidence interval obtained p-value = 0.000, there is a significant difference in callus image in both groups of patients post open reduction internal fixation non-articular tibia fracture. The linear regression calculated of callus assessment with bone-specific alkaline phosphatase obtained the value of R quadrat = 0.793, which showed that the formation of callus Hummer classification could predict the change in bone-specific alkaline phosphatase value by 79%.
CONCLUSION: The research found isometric exercise plantar flexor in patients post open reduction internal fixation non-articular tibia fracture enhances osteoblast activity and callus formation that will likely short the healing process time and prevent delayed union or non-union.
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Rice, Robert H., Blythe P. Durbin-Johnson, Michelle Salemi, Mary E. Schwartz, David M. Rocke e Brett S. Phinney. "Proteomic profiling of Pachyonychia congenita plantar callus". Journal of Proteomics 165 (agosto 2017): 132–37. http://dx.doi.org/10.1016/j.jprot.2017.06.017.
Testo completo
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Booth, J., e A. Mclnnes. "The aetiology and management of plantar callus formation". Journal of Wound Care 6, n. 9 (2 ottobre 1997): 427–30. http://dx.doi.org/10.12968/jowc.1997.6.9.427.
Testo completo
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Potter, J., e M. J. Potter. "Effect of callus removal on peak plantar pressures". Foot 10, n. 1 (marzo 2000): 23–26. http://dx.doi.org/10.1054/foot.2000.0576.
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Collier, Joann H., e Carol A. Brodbeck. "Assessing the Diabetic Foot: Plantar Callus and Pressure Sensation". Diabetes Educator 19, n. 6 (dicembre 1993): 503–8. http://dx.doi.org/10.1177/014572179301900605.
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Young, M. J., P. R. Cavanagh, G. Thomas, M. M. Johnson, H. Murray e A. J. M. Boulton. "The Effect of Callus Removal on Dynamic Plantar Foot Pressures in Diabetic Patients". Diabetic Medicine 9, n. 1 (2 gennaio 1992): 55–57. http://dx.doi.org/10.1111/j.1464-5491.1992.tb01714.x.
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Colagiuri, S., L. L. Marsden, V. Naidu e L. Taylor. "The use of orthotic devices to correct plantar callus in people with diabetes". Diabetes Research and Clinical Practice 28, n. 1 (aprile 1995): 29–34. http://dx.doi.org/10.1016/0168-8227(95)01050-n.
Testo completo
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Springett, K. P., M. F. Whiting e C. Marriott. "Epidemiology of plantar forefoot corns and callus, and the influence of dominant side". Foot 13, n. 1 (marzo 2003): 5–9. http://dx.doi.org/10.1016/s0958-2592(02)00112-8.
Testo completoTesi sul tema "Plantar callus"
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Wright, C. R. F. "The biophysical properties of plantar callus and the relationship between pressure and callus development and regression". Thesis, University of Salford, 2015. http://usir.salford.ac.uk/36946/.
Testo completoAbstract (sommario):
Plantar calluses are common skin lesions which often require professional treatment by podiatrists. They commonly present under prominent areas such as the metatarsal heads and can cause significant discomfort during ambulation. Furthermore, they are one of the known risk factors for ulceration in individuals with systemic conditions such as diabetes mellitus. Anecdotal evidence suggests that mechanical factors contribute to calluses and there are numerous studies linking callus to increased peak plantar pressure. However, whether callus is a result of increased pressure or vice versa remains unclear. Skin on other areas of the body has been shown to respond to external loading forces, but no research has specifically investigated the relationship between callus and pressure. A critical review of the literature explored the methods used for skin profiling through biophysical skin measurement. Skin hydration, distensibility and topography were revealed to be useful measurement parameters to characterise plantar skin and for this study, three devices were chosen for testing these parameters. However, as these devices have not received much attention for testing plantar callus in previous research, the first study investigated their repeatability on normal and callused plantar skin. These devices were shown to provide adequate measures of skin properties so they were then used in a larger scale study investigating the biophysical characteristics of normal and callused plantar skin. It was found that callused skin was less hydrated, less distensible, and rougher in texture than normal plantar skin. Work was then undertaken to develop a device that could apply loads to plantar skin in a safe manner so that the skin’s response to external loading could be assessed. A subsequent pilot study was conducted to assess whether normal plantar skin in individuals prone to callus would display callus-like skin changes as a result of increased vertical pressure applied by the skin loading device over a minimum period of six weeks. After the skin loading period, no effect could be observed in normal plantar skin properties. The reasons for this are explored in depth. A study was then undertaken in order to assess the effect of plantar pressure reduction in callused skin over a period of 12 weeks. Pressure reduction was achieved by using customised insoles worn by the study participants. No change in callused skin properties was observed and the reasons for this are explored in depth. These studies provide a strong starting point in understanding the link between pressure and callus and provide a foundation for further research.
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Bevans, John S. "Mechanical, neuropathic and metabolic factors in the formation of plantar callus in diabetes". Thesis, University of Salford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388486.
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Duffin, Anthony C., University of Western Sydney, of Science Technology and Environment College e of Science Food and Horticulture School. "Structural and functional changes in the feet of young people with Type 1 diabetes mellitus". THESIS_CSTE_SFH_Duffin_A.xml, 2002. http://handle.uws.edu.au:8081/1959.7/408.
Testo completoAbstract (sommario):
Diabetes can affect the structure and function of the foot, resulting in severe limitation of mobility and reduction of life expectancy. Early warning signs include limited joint mobility (LJM), soft tissue changes, high plantar pressure (HPP), high pressure time integrals (P/TI) and plantar callus. These abnormalities were examined in 216 young people with diabetes and 57 controls. The fingers, toes, ankle subtalar and first metatarsophalangeal joints shows reduced motion and the plantar aponeurosis was thicker in diabetic subjects. Skin thickness was the same for diabetic and control subjects. LJM in the feet was more common in males and older subjects. Subtalar and finger LJM was associated with early sensory nerve changes and finger LJM was associated with retinopathy and higher HbAtc. Thicker plantar aponeurosis was associated with male gander and larger feet. High peak pressure, high P/TI and callus were no more common in diabetic subjects than controls. However, high P/TI and callus were associated with early sensory nerve changes in young people with diabetes. Diabetic subjects with callus were significantly older than those without callus. Those with HPP had higher body mass index and less motion at the first MTP joints than those without HPP. Although plantar callus, HPP and high P/TI were no more common in young people with diabetes these abnormailities may be complicated by diabetes. Cushioning, custom orthoses or both in combination significantly reduced peak pressure and P/TI in diabetic subjects.Doctor of Philosophy (PhD)
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Daw, Julia. "Mechanically induced plantar hyperkeratosis". Thesis, University of Brighton, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.260938.
Testo completo
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Seto, Kazuhisa. "On the Complexity of the Hajos Calculus for Planar Graphs". 京都大学 (Kyoto University), 2010. http://hdl.handle.net/2433/120387.
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Souza, Isabel Cristina da CÃsta. "Biochemical characterization of callus laticÃferas species in response to salt stress and analysis of transcription osmotinas". Universidade Federal do CearÃ, 2015. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=15574.
Testo completoAbstract (sommario):
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel SuperiorCalotropis procera e Cryptostegia grandiflora sÃo plantas laticÃferas. Em seus fluidos laticÃferos, foram encontradas proteÃnas do tipo osmotina. A literatura reporta que osmotinas sÃo proteÃnas relacionadas com mecanismos de defesa vegetal em situaÃÃes de estresse biÃtico e/ou abiÃtico. Entretanto, ainda hà vÃrias inconsistÃncias nessa afirmaÃÃo. Nesse contexto, tÃcnicas in vitro de cultura de tecidos vegetais foram aplicadas como modelo para auxiliar na compreensÃo de como as cÃlulas de calos de C. procera e C. grandiflora respondem ao estresse salino, em termos bioquÃmicos, e se o nÃvel de transcritos para a osmotina seria aumentado em resposta à exposiÃÃo a NaCl. Para induÃÃo desse estresse, NaCl foi adicionado à formulaÃÃo nutritiva de Murashige e Skoog (MS), em concentraÃÃes crescentes (0, 20, 40, 60 e 80 mM). Os resultados mostram que os calos cultivados com NaCl a 80 mM tiveram o crescimento e o teor de umidade reduzidos, respectivamente, em 33% e 10%, em C. procera e de 83% e 39%, em C. grandiflora, em comparaÃÃo ao seu tratamento controle. Nessas mesmas condiÃÃes, foi observado um aumento nas concentraÃÃes dos Ãons Na+ e Cl- de, respectivamente, 98,9% e 98%, em C. procera, e de 98,8% e 96%, em C. grandiflora. Foi tambÃm observada diminuiÃÃo no teor de K+ nos calos tratados com NaCl a 80 mM. Essa reduÃÃo foi de 43%, em C. procera, e de 18% em C. grandiflora, quando comparado ao tratamento controle. Os calos tratados com NaCl a 80 mM, apresentaram uma tendÃncia de acÃmulo de prolina e aÃÃcares solÃveis, alcanÃando, respectivamente valores, 26% e 37% maiores em calos de C. procera, e 55,4% e 45% maiores, em calos de C. grandiflora, que aqueles em condiÃÃes controle. O aumento na atividade das enzimas que degradam H2O2 foi observado em calos de C. grandiflora submetidos a estresse salino, sugerindo um possÃvel dano oxidativo. Esse aumento foi de 73%, para a ascorbato peroxidase, e de 62% para a peroxidase do guaiacol, nos calos tratados com NaCl a 80 mM, em relaÃÃo ao controle. NÃo foi observada qualquer alteraÃÃo significante na atividade das enzimas do sistema antioxidativo em razÃo do estresse salino em calos de C. procera. Em relaÃÃo à transcriÃÃo da osmotina, foi avaliado o perfil de seus transcritos nos intervalos de tempo de 0, 2, 12, 24, 48 horas e de 4, 7, 14 e 28 dias sob estresse. Os transcritos de osmotina foram observados a partir de 12 horas de contato dos calos com NaCl a 80 mM, em ambas as espÃcies. Contudo, nos extratos proteicos dos calos de C. procera e C. grandiflora cultivados em condiÃÃes controle e de 80 mM de NaCl, nÃo foi detectada a presenÃa da proteÃna osmotina quando avaliado pelos ensaios de eletroforese, Dot blotting e espectrometria de massas. Assim, a avaliaÃÃo do estresse salino utilizando como modelo de estudo cÃlulas in vitro foi eficiente, fornecendo informaÃÃes do comportamento celular de duas espÃcies laticÃferas, mostrando suas alteraÃÃes fisiolÃgicas, bioquÃmicas e moleculares. Os resultados sugerem que o estresse salino favoreceu o aumento da transcriÃÃo do gene da osmotina em calos das duas espÃcies em estudo e permite propor uma possÃvel relaÃÃo das osmotinas dessas espÃcies com a tolerÃncia à salinidade. A falha em detectar as proteÃnas correspondentes aos genes propicia a concepÃÃo de vÃrias novas hipÃteses a serem validadas.
Calotropis procera e Cryptostegia grandiflora are laticiferous plants. It was found osmotin protein. The literature shows that the osmotinas are associated to plant defence mechanisms in situations of biotic or abiotic stress. However, there are still several inconsistencies in this hypothesis. In this context, it was used in vitro tissue culture techniques as model to assist in the understanding of how the C. procera and C. grandiflora callus cells respond to salt stress in biochemical terms, and whether the transcripts level for osmotin has raised in response to exposure to NaCl. It was added NaCl to the culture medium of Murashige e Skoog (MS) in increasing concentrations (0, 20, 40, 60 e 80 mM). The results show that callus treated with 80 mM NaCl have reduced the growth and the humidity percentage of respectively 33% and 10% in C. procera and 83% and 39% in C. grandiflora compared to the control treatment callus. Under the same conditions, it was seen an increase in ions concentrations of Na+ and Cl-, 98.9% and 98% in C. procera and 98.8% and 96% in C. grandiflora respectively. It was also seen a reduction in K+ level in callus treated with 80 mM NaCl, 43% in C. procera and 18% in C. Grandiflora, when compared to the control. The callus treated with 80 mM NaCl, showed a tendency of the proline accumulation and soluble sugars, increasing 26% and 37% in C. procera callus and 55.4% and 45% in C. grandiflora callus, respectively, when compared to control conditions. The increase in the activity of enzymes that break H2O2 has been observed in C. grandiflora callus under the salt stress, suggesting a possible oxidative damage, this increase was 73% in the ascorbate peroxidase activity and 62% in guaiacol peroxidase activity when compared to the activity of enzymes of the control callus with the treaty in 80 mM NaCl. None connection was seen between changes in the activity of the enzymes of the oxidative system and the salt stress in C. procera callus. It was evaluated the behaviour of osmotin in the osmotin transcription at 0, 2, 12, 24, 48 hours and at 4, 7, 14, 28 days of callus contact under stress. The osmotin transcripts were observed from 12 hours of contact of callus in 80mM NaCl in both species. However, it was not found osmotin by electrophoresis assays, dot blotting and mass spectrometry in the protein extracts of C. procera and C. grandiflora callus grown in control conditions and in 80 mM NaCl. Thus, the salt stress evaluation using in vitro cell model study was effective, providing cellular behaviour information for these two laticifers plants species showing their physiological, biochemical and molecular changes. The results suggest that the induced salt stress has favoured the increase of osmotin gene expression in both cases and suggests a possible relationship between osmotin of these species with the protection to salinity conditions. The failure to detect the proteins corresponding to genes provides the conception of several new hypotheses to be validated.
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Ribeiro, Beatriz Mateus. "Casas para um planeta pequeno". Master's thesis, Universidade de Lisboa, Faculdade de Arquitetura, 2017. http://hdl.handle.net/10400.5/15375.
Testo completoAbstract (sommario):
Dissertação de Mestrado Integrado em Arquitetura, com a especialização em Arquitetura apresentada na Faculdade de Arquitetura da Universidade de Lisboa para obtenção do grau de Mestre.info:eu-repo/semantics/publishedVersion
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Valdivia, Sepúlveda Carlos Christian. "Cultivo de callos de Vitis vinífera cv. Cabernet Sauvignon infectados con grapevine fan leaf virus (GFLV)". Tesis, Universidad de Chile, 2006. http://www.repositorio.uchile.cl/handle/2250/101813.
Testo completoAbstract (sommario):
Las enfermedades virales afectan tanto la calidad como la productividad de la vid, causando variados síntomas. Grapevine Fan Leaf Virus (Virus de la Hoja en Abanico de la Vid, GFLV) produce moteado y deformación de hojas, deformación de sarmientos, cuaja deficiente y maduración desuniforme.En Chile, la incidencia de este virus llega al 0,2%, mientras que las pérdidas en el rendimiento se han estimado hasta en un 12%. Puesto que los virus son de difícil estudio, se hace necesario el uso de métodos eficaces de mantención en laboratorio de este tipo de patógenos con fines de investigación, siendo el cultivo de callos infectados una de las técnicas empleadas.
Para establecer un medio de cultivo adecuado para mantener GFLV sobre callo de vid Cabernet Sauvignon, se realizaron dos ensayos. El primero para establecer la combinación de fitohormonas que induce el mayor crecimiento, y el segundo para determinar la mantención del virus en el callo después de un tiempo en cultivo in vitro. Se indujo el crecimiento de callo en un medio MS suplementado con 2,4-D (0,1; 0,5; 1,0 y 2,0 ppm) y BA (0,5; 1,0 y 2,0 ppm). El cultivo se mantuvo por 8 semanas. En el segundo ensayo, trozos de láminas infectadas con GFLV se colocaron sobre el medio que promovió el mayor crecimiento y se verificó la presencia de GFLV durante 8 semanas mediante test ELISA.
El crecimiento de los callos fue afectado principalmente por la concentración de 2,4-D, a mayor concentración, mayor crecimiento del callo. A mayor concentración de 2,4 D también se observa un marcado efecto del BA: concentraciones bajas de este regulador hormonal logran el mayor desarrollo de callo. 0,5 ppm de BA combinado con 1 y 2 ppm de 2,4-D presentaron el mayor crecimiento. Los callos infectados con GFLV presentaron un aspecto compacto y pardeado. La absorbancia observada en callos de 2 a 8 semanas fue al menos tres veces superior a la de tejido in vitro e in vivo infectados con GFLV, y más de 18 veces superior al control negativo, no existiendo diferencia significativa entre la absorbancia de los callos positivos al virus. Finalmente, se determinó que la carga viral de los callos no disminuyó al transcurrir el tiempo, por lo que se presume que el virus se multiplica junto con las células del callo.Diseases caused by viruses affect the quality and the productivity of grapevine causing several symptoms. Grapevine Fan Leaf Virus (GFLV) produces mottling and deformed leaves and shoots, fruit dropping and uneven ripening. Since the study of the viruses is very difficult, it is necessary an effective method of maintenance of this type of pathogens in laboratory with investigation aims, being the culture of infected callus one of the employed techniques. Two trials were made in order to establish a proper culture medium for maintaining GFLV on callus tissue of Cabernet Sauvignon grapevine. The first one was targeted to establish the growth regulator’s combination which induces the highest growing ratio. The second trial was focused on the long term maintenance of the virus within the callus. The callus growth was induced on MS medium suplemented with 2,4-D (0,1; 0,5; 1,0 and 2,0 ppm) and BA (0,5; 1,0 and 2,0 ppm). The culture was kept for 8 weeks. In the second trial, leaves sections infected with GFLV were placed on the medium that promoted the highest growth and the presence of GFLV was verified by ELISA test during the mentioned period.. The callus growth prooved to be influenced mainly by 2,4-D. A direct relation exists between the increasing 2,4-D concentration and the callus growth. At a higher concentration of 2,4-D a noticeable effect of the concentration of BA is also observed: low concentrations of this hormonal regulator result in a higher development of callus. 0,5 ppm of BA in combination with 1 and 2 ppm of 2,4-D displayed the highest growth. The infected calli with GFLV showed a brownish and compact aspect of the tissue. The absorbance measured in calli from 2 to 8 weeks was at least three times superior than the one of in vitro and in vivo tissue infected with GFLV, and 18 times superior than the negative control. A significant difference between the absorbance of the positive calli to the virus does not exist. Finally, the virus presence is not affected on long term culture, therefore it is presumed that the virus multiplies simultaneously to callus growth.
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Montanucci, Cleuza Aparecida da Rocha. "Caracterização botânica, avaliação da germinação de sementes e regeneração de plantas de Brugmansia suaveolens (Willd.). Bercht. & J. Presl". Universidade Estadual do Oeste do Paraná, 2011. http://tede.unioeste.br:8080/tede/handle/tede/1407.
Testo completoAbstract (sommario):
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Previous issue date: 2011-03-20Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
The knowledge of morphological and ecophysiological features ofBrugmansia suaveolens (Willd.).Bercht.& J. Presl is the first step towards the use of this species with biotechnological purpose. This study aimed to: 1) the morphological characteristics of specimens of B. suaveolens, 2) evaluation of in vitro germination rates under different conditions of seed´s treatment. 3) the establishment of an efficient regeneration protocol in B. suaveolens. We evaluated the rates of regeneration, the percentages of calli induction and calli size, germination of embryos, the number of embriogenic spots and the number of regenerated plantlets. As results, 22 individuals were collected and grouped into three different groups, differing only by flowers colors. The fruits showed mean values of: 975 mm long, 189 mm wide and 6.99 g of weight Seeds presented mean values of7 mm long, 6.00 mm width, 3.04 mm thicknessand mass of 0.39 g.The estimated period for initiation of the germination process without the presence of the tegument was 14 days. In all treatments there was an increased cumulative germination. Regarding the effect of pre-treatments can be observed that temperatures of 4 ºC and 50 ºC did not promote differences between treatments. Exposure to sulfuric acid and soaking the seeds in water for longer periods of reduced germination. The presence of gibberellic acid caused inhibition of embryo development in vitro. In the development of regeneration protocols, the establishment of plants from mature embryos of this species, the percentage of calli induction ranged from 26 to 100%, the ratio seedling / callus induced ranged from 0 to 0.84 and the efficiency of regeneration ranged from 0 to 32%. The dosages of 0.5 mg L-1 2.4 D and 1.0 mg L-1 KIN were more efficient regarding to calli induction, calli size, number of green spots points and regenerated plantlets. High concentrations of growth regulators (1 mg L-1 2-4 D and 1.0 mg L-1 KIN) were inhibitory to calli formation and regeneration, the absence of these regulators promoted the formation of calli but any plantlets of B.suaveolens were gotten
O conhecimento das características morfológicas e ecofisiológicas de plantas de Brugmansia suaveolens (Willd.). Bercht. & J. Preslé o primeiro passo para o uso desta espécie com finalidade biotecnológica. Este trabalho teve como objetivos: 1) a caracterização morfológica de acessos da B. suaveolens; 2) avaliação do comportamento germinativo das sementes in vitro sob diferentes condições de tratamento e 3) o estabelecimento de protocolo de regeneração eficiente de B. suaveolens. Foram avaliados os índices de regeneração, além das porcentagens de indução e tamanho de calos, da germinação de embriões, o número de pontuações verdes e o número de plântulas regeneradas. Como resultados obtidos, 22 indivíduos de B. suaveolens foram coletados e agrupados em três grupos, diferindo apenas nas cores das flores. Os frutos apresentaram valores médios de: 975mm de comprimento, 189 mm de largura e 6,99 g de massa, as sementes de 7mm de comprimento, 6 mm de largura, 3,04mm e espessura e massa de 0,39 g. O período estimado para o início do processo germinativo sem a presença do tegumento foi de 14 dias. Em todos os tratamentos observou-se uma germinação acumulada aumentada. Em relação ao efeito dos tratamentos pode-se observar que temperaturas de 4 ºC e 50 ºC não propiciaram diferenças estatísticas entre os tratamentos. A exposição ao ácido sulfúrico e a embebição das sementes em água por períodos maiores que 24 horas, reduziram a germinação. A presença do ácido giberélico promoveu a inibição do desenvolvimento dos embriões in vitro. No desenvolvimento do protocolo de regeneração para o estabelecimento de plantas a partir de embriões maduros para esta espécie, a porcentagem de indução de calos variou de 26a100%, a razão plântula/calo induzido variou de 0 a 0,84 e a eficiência de regeneração variou de 0a32%. As dosagens de 0,5mgL-1 de 2,4-D e 1,0mg L-1 KIN foram as mais eficientes nas respostas para indução de calos, no tamanho de calos, no número de pontos embriogênicos e plântulas regeneradas. Altas concentrações de reguladores de crescimento (1,0mgL-1 de 2,4-D e 1,0mg L-1 KIN) inibiram a calogênese e regeneração; a ausência destes reguladores promoveram a formação de calos mas não a regeneração de plantas de B. suaveolens
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Vila, Porras Gumercindo Raúl. "Análisis del uso de plantas medicinales en mercados de abastos del distrito de Ventanilla-Callao, 2007". Bachelor's thesis, Universidad Nacional Mayor de San Marcos, 2009. https://hdl.handle.net/20.500.12672/1630.
Testo completoAbstract (sommario):
El Perú es un país poseedor de una gran biodiversidad y experiencia en el uso tradicional de plantas medicinales, fuente de recursos naturales para la investigación y desarrollo de fitomedicamentos. El objetivo del presente trabajo es analizar el uso y utilización de plantas medicinales en los clientes de cuatro mercados de abastos del distrito de Ventanilla- callao, junio – diciembre 2007; para este efecto se evaluaron a 97 usuarios de plantas medicinales mediante una encuesta, para determinar la necesidad de ser orientados profesionalmente, y se evaluaron a 20 vendedores de plantas medicinales con la finalidad de identificar su formación en plantas medicinales. A las encuestas se les efectuó un análisis de validez y confiabilidad por el método de Coeficiente de Consistencia Interna Alfa de Cronbach para determinar su significancia estadística. Se les codificó y creó una base de datos en el programa SPPSS v 12. En los usuarios de plantas medicinales se ha determinado la necesidad de orientación y educación profesional sobre el uso de plantas medicinales; en los vendedores de plantas se ha determinado que no tienen una formación académica sobre el uso de plantas medicinales, por lo que en el presente trabajo de investigación se propone una serie de herramientas técnicas en Consejería Farmacéutica de plantas medicinales en los establecimientos farmacéuticos como farmacias y boticas.Peru is a country in possession of a great biodiversity and experience in the use of traditional medicinal plants, a source of natural resources for research and development of phytomedicines. The purpose of this study to use of medicinal plats in four markets of the Ventanilla district- Callao, june – December 2007; to this effect were assessed to 97 users of medicinal plants through a survey to determine the need to be professionally oriented, and 20 sellers in the plant with the intention of measuring its formation in plants medicinal. In the surveys were conducted an analysis of validity and reliability of the method of internal consistency coefficient of Cronbach Alfa to determine their statistical significance. They were codified and created a database on the program SPSS v12. In users of medicinal plants has identified a need for professional guidance and education on the use of medicinal plants; sellers in the plant have been determined to have no formal training on the use of medicinal plants, so in this research work proposes a set of technical tools in pharmaceutical counseling for the use and utilization of medicinal plants and pharmaceuticals in drugstores and pharmacies in our country.
Tesis
Libri sul tema "Plantar callus"
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Mejía, Luis Miguel Alvarez. Plantas de la región centro-sur de Caldas. Manizales, Colombia: Editorial Universidad de Caldas, 2007.
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Ruiz, Carmen Moreno. Guía de plantas de las calles, plazas, parques y jardines de Fuengirola. [Málaga]: Centro de Ediciones de la Diputación de Málaga, 1995.
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Bourrier, Régis. Les réseaux d'assainissement: Calculs, applications, perspectives. 2a ed. Paris: Lavoisier, 1985.
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1931-2008, Hargan Harold David, a cura di. Callous disregard: An inside story of the Paducah Gaseous Diffusion Plant : recollections of Harold "Hotsy" Hargan, nuclear whistleblower and arms race casualty (as told to Sandy Stricker). [United States]: Lulu.com, 2010.
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Underhill, Terry L. Heaths & heathers: The growerʼs encyclopedia. Newton Abbot: David & Charles, 1990.
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Luengo, José Guillermo Merck. La Botica de la Calle Mayor de Cartagena. Murcia: Real Academia Alfonso X el Sabio, 1994.
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Borzyh, Stanislav. Urban evolution. ru: INFRA-M Academic Publishing LLC., 2022. http://dx.doi.org/10.12737/1841828.
Testo completoAbstract (sommario):
The monograph is devoted to evolution, but in the form that man gave it. It is assumed that unnatural conditions of its flow were created in cities and near them, which changed the logic of its functioning, but this has become especially noticeable over the past hundred years, during which the entire planet was included in the orbit of our influence. This made it possible to unite the Earth into one whole, but at the same time it transformed the work of natural selection, turning it into an artificial one that concerns everyone and everything, without any exceptions. Accordingly, three planes of its unfolding are considered, namely: geography, the biosphere and our species, in each of which the same dynamics of its implementation can be traced. From all this, it is concluded that today there is no wild and inherent in the whole history of his version, but the one that prevails is that we, consciously and not, planted on this space object with all its inhabitants. This new version of it is proposed to be called urban revolution - by the name of the site of its unfolding and everything that is associated with it, but it is repeatedly emphasized that the essence of the process has remained the same, the scene where it is carried out has simply been transformed.
It is intended for both specialists and the general public.
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Ninul, Anatolij Sergeevič. Tenzornaja trigonometrija: Teorija i prilozenija / Theory and Applications /. Moscow, Russia: Mir Publisher, 2004.
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Ninul, Anatolij Sergeevič. Tensor Trigonometry. Moscow, Russia: Fizmatlit Publisher, 2021.
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Tanner, Natalie Anne. The effect of an alphahydroxy acid on plantar forefoot callus: A preliminary study. 1999.
Cerca il testo completoCapitoli di libri sul tema "Plantar callus"
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Neumann, Karl-Hermann, Ashwani Kumar e Jafargholi Imani. "Callus Cultures". In Plant Cell and Tissue Culture – A Tool in Biotechnology, 25–59. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-49098-0_3.
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Neumann, Karl-Hermann, Jafargholi Imani e Ashwani Kumar. "Callus Cultures". In Plant Cell and Tissue Culture - A Tool in Biotechnology, 13–42. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-540-93883-5_3.
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Guericke, Otto. "Planetary Motion". In The New (So-Called) Magdeburg Experiments of Otto Von Guericke, 331. Dordrecht: Springer Netherlands, 1994. http://dx.doi.org/10.1007/978-94-011-2010-4_138.
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Khare, C. P. "Calamus rotang Linn." In Indian Medicinal Plants, 1. New York, NY: Springer New York, 2007. http://dx.doi.org/10.1007/978-0-387-70638-2_263.
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Khare, C. P. "Calamus tenuis Roxb." In Indian Medicinal Plants, 1. New York, NY: Springer New York, 2007. http://dx.doi.org/10.1007/978-0-387-70638-2_264.
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Khare, C. P. "Acorus calamus Linn." In Indian Medicinal Plants, 1. New York, NY: Springer New York, 2007. http://dx.doi.org/10.1007/978-0-387-70638-2_38.
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Radojević, Lj, N. Djordjević e M. Guć-Šćekić. "In Vitro Embryogenic Callus Formation in Chimonanthus". In Somatic Cell Genetics of Woody Plants, 51–52. Dordrecht: Springer Netherlands, 1988. http://dx.doi.org/10.1007/978-94-009-2811-4_6.
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Grout, B. W. W. "Cryopreservation of Protoplast, Suspension and Callus Cultures". In Genetic Preservation of Plant Cells in Vitro, 29–46. Berlin, Heidelberg: Springer Berlin Heidelberg, 1995. http://dx.doi.org/10.1007/978-3-642-78661-7_3.
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Vasil, Indra K., e Vimla Vasil. "Embryogenic callus, cell suspension and protoplast cultures of cereals". In Plant Tissue Culture Manual, 227–42. Dordrecht: Springer Netherlands, 1991. http://dx.doi.org/10.1007/978-94-009-0103-2_12.
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Bagni, Nello, e Marisa Mengoli. "Characterization of a carrot callus line resistant to high concentrations of putrescine". In Polyamines in Plants, 169–78. Dordrecht: Springer Netherlands, 1985. http://dx.doi.org/10.1007/978-94-009-5171-6_15.
Testo completoAtti di convegni sul tema "Plantar callus"
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Taufik, Nasyaruddin Herry, e Nurjannah. "Effect of Isometric Plantar Flexor Muscles Exercises on the Callus Formation of Patients with Tibial Shaft Fracture". In The 2nd Syiah Kuala International Conference on Medicine and Health Sciences. SCITEPRESS - Science and Technology Publications, 2018. http://dx.doi.org/10.5220/0008792402330236.
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Stupko, V. Yu, N. V. Zobova e N. A. Gaevsky. "Features of the analysis of the photosynthetic activity dynamics of Triticum L. callus cultures". In IX Congress of society physiologists of plants of Russia "Plant physiology is the basis for creating plants of the future. Kazan University Press, 2019. http://dx.doi.org/10.26907/978-5-00130-204-9-2019-414.
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suzuki, kakeru. "Establishment of an in vitro translation system from rice callus extracts". In ASPB PLANT BIOLOGY 2020. USA: ASPB, 2020. http://dx.doi.org/10.46678/pb.20.1052637.
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"Intra-callus variability of Oryza sativa L. androgenic doubled haploids". In Plant Genetics, Genomics, Bioinformatics, and Biotechnology. Novosibirsk ICG SB RAS 2021, 2021. http://dx.doi.org/10.18699/plantgen2021-081.
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Sundyreva, M. A., E. O. Lutsky e A. E. Mishko. "Stilbene biosynthesis in callus culture of grapes of different resistance to pathogens". In 2nd International Scientific Conference "Plants and Microbes: the Future of Biotechnology". PLAMIC2020 Organizing committee, 2020. http://dx.doi.org/10.28983/plamic2020.239.
Testo completoAbstract (sommario):
Low gene expression of CHI and CHS and high expression of PAL and STS were detected in varieties with a high content of stilbenes. A feature of varieties with low stilbene production was a weak level of PAL gene expression.
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Kruglova, N. N., e O. A. Seldimirova. "The “embryo in planta – callus in vitro” system: cytophysiological aspects (by wheat example)". In 2nd International Scientific Conference "Plants and Microbes: the Future of Biotechnology". PLAMIC2020 Organizing committee, 2020. http://dx.doi.org/10.28983/plamic2020.132.
Testo completoAbstract (sommario):
Plant regeneration from calli in vitro is an integral part of a number of biotechnologies. Immature embryos (IE) are particularly promising as explants for obtaining morphogenic calli (MC) in cereals.
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Rivai, Reza Ramdan, Yupi Isnaini e Yuzammi. "Elucidation of the Radiosensitivity Level of Amorphophallus paeoniifolius (Dennst.) Nicolson Embryogenic Callus Induced by Gamma Ray Irradiation". In International Electronic Conference on Plant Sciences. Basel Switzerland: MDPI, 2022. http://dx.doi.org/10.3390/iecps2021-11951.
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"Optimization of Sterilization Method And Callus Induction Of Cocos Nucifera Linn. Var. Matag from Inflorescence". In International Conference on Plant, Marine and Environmental Sciences. International Institute of Chemical, Biological & Environmental Engineering, 2015. http://dx.doi.org/10.15242/iicbe.c0115029.
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Shvets, D. Yu, e B. R. Kuluev. "In vivo callus formation on the surface of tubers of Manchu tubergourd (Thladiantha dubia, Cucurbitaceae)". In 2nd International Scientific Conference "Plants and Microbes: the Future of Biotechnology". PLAMIC2020 Organizing committee, 2020. http://dx.doi.org/10.28983/plamic2020.228.
Testo completoAbstract (sommario):
For the first time, shingles of callus-like structures were found in Thladiantha dubia. Of these formations, shoots and roots are intensively regenerated in vivo. Such a mechanism underlies the active vegetative propagation and wide distribution of this invasive species.
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kapoor, karuna. "Role and formation of callose plugs during pollen tube growth". In ASPB PLANT BIOLOGY 2020. USA: ASPB, 2020. http://dx.doi.org/10.46678/pb.20.1050105.
Testo completoRapporti di organizzazioni sul tema "Plantar callus"
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Sink, Ken, Shamay Izhar e Abraham Nachmias. Asymmetric Somatic Hybridization: Developing a Gene Transfer System for Solanaceous Vegetable Crops. United States Department of Agriculture, febbraio 1996. http://dx.doi.org/10.32747/1996.7613010.bard.
Testo completoAbstract (sommario):
Highly asymmetric somatic hybrid plants were obtained by PEG/DMSO fusion of gamma irradiated (100, 250, 7500 and 1000 Gy) protoplasts of a (KmR-) interspecific hybrid Lycopersicon esculentum x L. pennellii (EP) with protoplasts of eggplant (E). Somatic hybrid calli were selected based on kanamycin resistance and verified by PCR of the NptII gene, RAPD's and Southern's using potato rDNA pTHG2 probes. Flow cytometry indicated all hybrid calli that did not regenerate shoots were 5-9n. Three asymmetric plants regenerated only from callus close to 4n and such calli oly occurred when EP received 100 Gy. The asymmetric plants had eggplant morphology and regenerated from one hybrid callus with 6.29 average size tomato chromosomes. Limited amounts of EP DNA were found in the three somatic hybrid plants H18-1 to -3 by dot-blot hybridization with probe pTHG2, to be equivalent to 6.23, 5.41, and 5.95 % EP, respectively. RFLP analysis of Lycopersicon esculentum and L. pennellii specific chromosomes revealed that only fragments of 8 to 10 out of the 24 EP chromosomes are present in the asymmetric plants. Transgenic plants 2-3, 2-4 and 10-3 were found resistant to verticillium; suggesting successful transfer of the Ve complex from S. torvum to eggplant.
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Handa, Avtar K., Yuval Eshdat, Avichai Perl, Bruce A. Watkins, Doron Holland e David Levy. Enhancing Quality Attributes of Potato and Tomato by Modifying and Controlling their Oxidative Stress Outcome. United States Department of Agriculture, maggio 2004. http://dx.doi.org/10.32747/2004.7586532.bard.
Testo completoAbstract (sommario):
General The final goal and overall objective of the current research has been to modify lipid hydroperoxidation in order to create desirable phenotypes in two important crops, potato and tomato, which normally are exposed to abiotic stress associated with such oxidation. The specific original objectives were: (i) the roles of lipoxygenase (LOX) and phospholipids hydroperoxide glutathione peroxidase (PHGPx) in regulating endogenous levels of lipid peroxidation in plant tissues; (ii) the effect of modified lipid peroxidation on fruit ripening, tuber quality, crop productivity and abiotic stress tolerance; (iii) the effect of simultaneous reduction of LOX and increase of PHGPx activities on fruit ripening and tuber quality; and (iv) the role of lipid peroxidation on expression of specific genes. We proposed to accomplish the research goal by genetic engineering of the metabolic activities of LOX and PHGPx using regulatable and tissue specific promoters, and study of the relationships between these two consecutive enzymes in the metabolism and catabolism of phospholipids hydroperoxides. USA Significant progress was made in accomplishing all objectives of proposed research. Due to inability to regenerate tomato plants after transforming with 35S-PHGPx chimeric gene construct, the role of low catalase induced oxidative stress instead of PHGPx was evaluated on agronomical performance of tomato plant and fruit quality attributes. Effects of polyamine, that protects DNA from oxidative stress, were also evaluated. The transgenic plants under expressing lipoxygenase (LOX-sup) were crossed with catalase antisense (CAT-anti) plants or polyamine over producing plants (SAM-over) and the lines homozygous for the two transgenes were selected. Agronomical performance of these line showed that low catalase induced oxidative stress negatively affected growth and development of tomato plants and resulted in a massive change in fruit gene expression. These effects of low catalase activity induced oxidative stress, including the massive shift in gene expression, were greatly overcome by the low lipoxygenase activity. Collectively results show that oxidative stress plays significant role in plant growth including the fruit growth. These results also for the first time indicated that a crosstalk between oxidative stress and lipoxygenase regulated processes determine the outcome during plant growth and development. Israel Regarding PHGPx, most of the study has concentrated on the first and the last specific objectives, since it became evident that plant transformation with this gene is not obvious. Following inability to achieve efficient transformation of potato and tomato using a variety of promoters, model plant systems (tobacco and potato cell cultures, tobacco calli and plantlets, and Arabidopsis) were used to establish the factors and to study the obstacles which prohibited the regeneration of plants carrying the genetic machinery for overproduction of PHGPx. Our results clearly demonstrate that while genetic transformation and over-expression of PHGPx occurs in pre-developmental tissue stage (cell culture, calli clusters) or in completed plant (Arabidopsis), it is likely that over-expression of this enzyme before tissue differentiation is leading to a halt of the regeneration process. To support this assumption, experiments, in which genetic engineering of a point-mutated PHGPx gene enable transformation and over-expression in plants of PhSPY modified in its catalytic site and thus inactive enzymatically, were successfully carried out. These combined results strongly suggest, that if in fact, like in animals and as we established in vitro, the plant PHGPx exhibits PH peroxidase activity, these peroxides are vital for the organisms developmental process.
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CORPS OF ENGINEERS WASHINGTON DC. Plant: Radio Frequency and Call Sign Assignments. Fort Belvoir, VA: Defense Technical Information Center, settembre 1986. http://dx.doi.org/10.21236/ada404085.
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Morin, Shai, Gregory Walker, Linda Walling e Asaph Aharoni. Identifying Arabidopsis thaliana Defense Genes to Phloem-feeding Insects. United States Department of Agriculture, febbraio 2013. http://dx.doi.org/10.32747/2013.7699836.bard.
Testo completoAbstract (sommario):
The whitefly (Bemisia tabaci) is a serious agricultural pest that afflicts a wide variety of ornamental and vegetable crop species. To enable survival on a great diversity of host plants, whiteflies must have the ability to avoid or detoxify numerous different plant defensive chemicals. Such toxins include a group of insect-deterrent molecules called glucosinolates (GSs), which also provide the pungent taste of Brassica vegetables such as radish and cabbage. In our BARD grant, we used the whitefly B. tabaci and Arabidopsis (a Brassica plant model) defense mutants and transgenic lines, to gain comprehensive understanding both on plant defense pathways against whiteflies and whitefly defense strategies against plants. Our major focus was on GSs. We produced transgenic Arabidopsis plants accumulating high levels of GSs. At the first step, we examined how exposure to high levels of GSs affects decision making and performance of whiteflies when provided plants with normal levels or high levels of GSs. Our major conclusions can be divided into three: (I) exposure to plants accumulating high levels of GSs, negatively affected the performance of both whitefly adult females and immature; (II) whitefly adult females are likely to be capable of sensing different levels of GSs in their host plants and are able to choose, for oviposition, the host plant on which their offspring survive and develop better (preference-performance relationship); (III) the dual presence of plants with normal levels and high levels of GSs, confused whitefly adult females, and led to difficulties in making a choice between the different host plants. These findings have an applicative perspective. Whiteflies are known as a serious pest of Brassica cropping systems. If the differences found here on adjacent small plants translate to field situations, intercropping with closely-related Brassica cultivars could negatively influence whitefly population build-up. At the second step, we characterized the defensive mechanisms whiteflies use to detoxify GSs and other plant toxins. We identified five detoxification genes, which can be considered as putative "key" general induced detoxifiers because their expression-levels responded to several unrelated plant toxic compounds. This knowledge is currently used (using new funding) to develop a new technology that will allow the production of pestresistant crops capable of protecting themselves from whiteflies by silencing insect detoxification genes without which successful host utilization can not occur. Finally, we made an effort to identify defense genes that deter whitefly performance, by infesting with whiteflies, wild-type and defense mutated Arabidopsis plants. The infested plants were used to construct deep-sequencing expression libraries. The 30- 50 million sequence reads per library, provide an unbiased and quantitative assessment of gene expression and contain sequences from both Arabidopsis and whiteflies. Therefore, the libraries give us sequence data that can be mined for both the plant and insect gene expression responses. An intensive analysis of these datasets is underway. We also conducted electrical penetration graph (EPG) recordings of whiteflies feeding on Arabidopsis wild-type and defense mutant plants in order to determine the time-point and feeding behavior in which plant-defense genes are expressed. We are in the process of analyzing the recordings and calculating 125 feeding behavior parameters for each whitefly. From the analyses conducted so far we conclude that the Arabidopsis defense mutants do not affect adult feeding behavior in the same manner that they affect immatures development. Analysis of the immatures feeding behavior is not yet completed, but if it shows the same disconnect between feeding behavior data and developmental rate data, we would conclude that the differences in the defense mutants are due to a qualitative effect based on the chemical constituency of the phloem sap.
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Delmer, Deborah P., e Prem S. Chourey. The Importance of the Enzyme Sucrose Synthase for Cell Wall Synthesis in Plants. United States Department of Agriculture, ottobre 1994. http://dx.doi.org/10.32747/1994.7568771.bard.
Testo completoAbstract (sommario):
The goal of this work was to understand the role of the enzyme sucrose synthase (SuSy) in synthesis of cellulose and callose in plants. The work resulting from the this grant leads to a number of conclusions. SuSy clearly plays diverse roles in carbon metabolism. It can associate with the plasma membrane of cells undergoing rapid cellulose deposition, such as cotton fibers, developing maize endosperm, gravistimulated pulvini, and transfer cells of the cotton seed. It is also concentrated at sites of high callose deposition (tapetal cells; cell plates). When SuSy levels are lowered by mutation or by anti-sense technology, cell walls undergo degeneration (maize endosperm) and show reduced levels of cellulose (potato tubers). In sum, our evidence has very much strengthened the concept that SuSy does function in the plasma membrane to channel carbon from sucrose via UDP-glucose to glucan synthase complexes. Soluble SuSy also clearly plays a role in providing carbon for starch synthesis and respiration. Surprisingly, we found that the cotton seed is one unique case where SuSy apparently does not play a role in starch synthesis. Current evidence in sum suggests that no specific SuSy gene encodes the membrane-associated form, although in maize the SS 1 form of SuSy may be most important for cell wall synthesis in the early stages of endosperm development. Work is still in progress to determine what does control membrane localization - and the current evidence we have favors a role for Ca2+, and possibly also protein phosphorylation by differentially regulated protein kinases. Finally, we have discovered for the first time, a major new family of genes that encode the catalytic subunit of the cellulose synthase of plants - a result that has been widely cited and opens many new approaches for the study of this important plant function.
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Coplin, David L., Shulamit Manulis e Isaac Barash. roles Hrp-dependent effector proteins and hrp gene regulation as determinants of virulence and host-specificity in Erwinia stewartii and E. herbicola pvs. gypsophilae and betae. United States Department of Agriculture, giugno 2005. http://dx.doi.org/10.32747/2005.7587216.bard.
Testo completoAbstract (sommario):
Gram-negative plant pathogenic bacteria employ specialized type-III secretion systems (TTSS) to deliver an arsenal of pathogenicity proteins directly into host cells. These secretion systems are encoded by hrp genes (for hypersensitive response and pathogenicity) and the effector proteins by so-called dsp or avr genes. The functions of effectors are to enable bacterial multiplication by damaging host cells and/or by blocking host defenses. We characterized essential hrp gene clusters in the Stewart's Wilt of maize pathogen, Pantoea stewartii subsp. stewartii (Pnss; formerly Erwinia stewartii) and the gall-forming bacterium, Pantoea agglomerans (formerly Erwinia herbicola) pvs. gypsophilae (Pag) and betae (Pab). We proposed that the virulence and host specificity of these pathogens is a function of a) the perception of specific host signals resulting in bacterial hrp gene expression and b) the action of specialized signal proteins (i.e. Hrp effectors) delivered into the plant cell. The specific objectives of the proposal were: 1) How is the expression of the hrp and effector genes regulated in response to host cell contact and the apoplastic environment? 2) What additional effector proteins are involved in pathogenicity? 3) Do the presently known Pantoea effector proteins enter host cells? 4) What host proteins interact with these effectors? We characterized the components of the hrp regulatory cascade (HrpXY ->7 HrpS ->7 HrpL ->7 hrp promoters), showed that they are conserved in both Pnss and Fag, and discovered that the regulation of the hrpS promoter (hrpSp) may be a key point in integrating apoplastic signals. We also analyzed the promoters recognized by HrpL and demonstrated the relationship between their composition and efficiency. Moreover, we showed that promoter strength can influence disease expression. In Pnss, we found that the HrpXY two-component signal system may sense the metabolic status of the bacterium and is required for full hrp gene expression in planta. In both species, acyl-homoserine lactone-mediated quorum sensing may also regulate epiphytic fitness and/or pathogenicity. A common Hrp effector protein, DspE/WtsE, is conserved and required for virulence of both species. When introduced into corn cells, Pnss WtsE protein caused water-soaked lesions. In other plants, it either caused cell death or acted as an Avr determinant. Using a yeast- two-hybrid system, WtsE was shown to interact with a number of maize signal transduction proteins that are likely to have roles in either programmed cell death or disease resistance. In Pag and Pab, we have characterized the effector proteins HsvG, HsvB and PthG. HsvG and HsvB are homologous proteins that determine host specificity of Pag and Pab on gypsophila and beet, respectively. Both possess a transcriptional activation domain that functions in yeast. PthG was found to act as an Avr determinant on multiple beet species, but was required for virulence on gypsophila. In addition, we demonstrated that PthG acts within the host cell. Additional effector genes have been characterized on the pathogenicity plasmid, pPATHₚₐg, in Pag. A screen for HrpL- regulated genes in Pnsspointed up 18 candidate effector proteins and four of these were required for full virulence. It is now well established that the virulence of Gram-negative plant pathogenic bacteria is governed by Hrp-dependent effector proteins. However; the mode of action of many effectors is still unresolved. This BARD supported research will significantly contribute to the understanding of how Hrp effectors operate in Pantoea spp. and how they control host specificity and affect symptom production. This may lead to novel approaches for genetically engineering plants resistant to a wide range of bacterial pathogens by inactivating the Hrp effectors with "plantabodies" or modifying their receptors, thereby blocking the induction of the susceptible response. Alternatively, innovative technologies could be used to interfere with the Hrp regulatory cascade by blocking a critical step or mimicking plant or quorum sensing signals.
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Davis, Eric L., Yuji Oka, Amit Gal-On, Todd Wehner e Aaron Zelcer. Broad-spectrum Resistance to Root-Knot Nematodes in Transgenic Cucurbits. United States Department of Agriculture, giugno 2013. http://dx.doi.org/10.32747/2013.7593389.bard.
Testo completoAbstract (sommario):
Root-knot nematodes (RKN), Meloidogyne spp., are extremely destructive pathogens of cucurbit crops grown in the United States and Israel. The safety and environmental concerns of toxic nematicides, and limited sources of natural cucurbit resistance to the four major species of Meloidogyne that threaten these crops in Israel and the U.S., have emphasized the use of biotechnology to develop cucurbits with novel RKN resistance. The U.S. scientists have identified over 40 unique RKN parasitism genes that encode nematode secretions involved in successful plant root infection by RKN, and they have demonstrated that expression of a double-stranded RNA (dsRNA) complementary to a RKN parasitism gene (called 16DIO) in Arabidopsis thaliana induced RNA interference (RNAi)-mediated silencing of the RKN16DlO gene and produced transgenic plants with strong resistance to all four major RKN species. The expression 8D05 parasitism gene was found to coincide with the timing of upregulation of NtCel7 promoter (identified to be upregulated in giantcells by US scientists). NtCel7 promoter was used to express the genes at the right time (early stages of infection) and in the right place (giant-cells) in transgenic plants. US partners produced NtCel7 (nematode-induced promoter)-driven 16DlO-RNAi and 8DOS-RNAi constructs, pHANNIBAL 4D03-RNAi construct and modified 16DlO-RNAi construct (for increased RNAi expression and efficacy) for cucurbit transformation in Israel. In Arabidopsis, some 16DlO-RNAi plant lines show greater levels of resistance to M. incognita than others, and within these lines resistance of greater than 90% reduction in infection is observed among almost all replicates in US. The level of observed nematode resistance is likely to be directly correlated with the level of RNAi expression in individual plants. In Israel, all the RKN parasitism genes-RNAi constructs were successfully transformed into cucumber and melon. The transgenic lines were evaluated for expression of the transgene siRNA in leaves and roots. Those displaying transgene siRNA accumulation were passed on for nematode resistance analysis. Rl seedlings from different lines were subjected to evaluation for resistance to M. javanica. None of the lines was resistant to the nematode in contrast with US partner's results in Arabidopsis. This could be for the following reasons: a) The level of transgene siRNA was insufficient in cucumber and tomato to cause resislance. b) 111e nemalode species on cucwnber IIlay be different ur act in a different manner. c) The assay was performed in soil with a high level of nematode inoculation, and not in petri dish, which may not permit the observation of a low level of resistance.
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Jordan, Ramon L., Abed Gera, Hei-Ti Hsu, Andre Franck e Gad Loebenstein. Detection and Diagnosis of Virus Diseases of Pelargonium. United States Department of Agriculture, luglio 1994. http://dx.doi.org/10.32747/1994.7568793.bard.
Testo completoAbstract (sommario):
Pelargonium (Geranium) is the number one pot plant in many areas of the United States and Europe. Israel and the U.S. send to Europe rooted cuttings, foundation stocks and finished plants to supply a certain share of the market. Geraniums are propagated mainly vegetatively from cuttings. Consequently, viral diseases have been and remain a major threat to the production and quality of the crop. Among the viruses isolated from naturally infected geraniums, 11 are not specific to Pelargonium and occur in other crops while 6 other viruses seem to be limited to geranium. However, several of these viruses are not sufficiently characterized to conclude that they are distinct agents and their nomenclature and taxonomy are confusing. The ability to separate, distinguish and detect the different viruses in geranium will overcome obstacles te developing effective detection and certification schemes. Our focus was to further characterize some of these viruses and develop better methods for their detection and control. These viruses include: isolates of pelargonium line pattern virus (PLPV), pelargonium ringspot virus (PelRSV), pelargonium flower break virus (PFBV), pelargonium leaf curl (PLCV), and tomato ringspot virus (TomRSV). Twelve hybridoma cell lines secreting monoclonal antibodies specific to a geranium isolate of TomRSV were produced. These antibodies are currently being characterized and will be tested for the ability to detect TomRSV in infected geraniums. The biological, biochemical and serological properties of four isometric viruses - PLPV, PelRSV, and PFBV (and a PelRSV-like isolate from Italy called GR57) isolated from geraniums exhibiting line and ring pattern or flower break symptoms - and an isolate ol elderbeny latent virus (ELV; which the literature indicates is the same as PelRSV) have been determined Cloned cDNA copies of the genomic RNAs of these viruses were sequenced and the sizes and locations of predicted viral proteins deduced. A portion of the putative replicase genes was also sequenced from cloned RT-PCR fragments. We have shown that, when compared to the published biochemical and serological properties, and sequences and genome organizations of other small isometric plant viruses, all of these viruses should each be considered new, distinct members of the Carmovirus group of the family Tombusviridae. Hybridization assays using recombinant DNA probes also demonstrated that PLPV, PelRSV, and ELV produce only one subgenomic RNA in infected plants. This unusual property of the gene expression of these three viruses suggests that they are unique among the Carmoviruses. The development of new technologies for the detection of these viruses in geranium was also demonstrated. Hybridization probes developed to PFBV (radioactively-labeled cRNA riboprobes) and to PLPV (non-radioactive digoxigenin-labeled cDNAs) were generally shown to be no more sensitive for the detection of virus in infected plants than the standard ELISA serology-based assays. However, a reverse transcriptase-polymerase chain reaction assay was shown to be over 1000 times more sensitive in detecting PFBV in leaf extracts of infected geranium than was ELISA. This research has lead to a better understanding of the identity of the viruses infecting pelargonium and to the development of new tools that can be used in an improved scheme of providing virus-indexed pelargonium plants. The sequence information, and the serological and cloned DNA probes generated from this work, will allow the application of these new tools for virus detection, which will be useful in domestic and international indexing programs which are essential for the production of virus-free germplasm both for domestic markets and the international exchange of plant material.
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Barg, Rivka, Kendal D. Hirschi, Avner Silber, Gozal Ben-Hayyim, Yechiam Salts e Marla Binzel. Combining Elevated Levels of Membrane Fatty Acid Desaturation and Vacuolar H+ -pyrophosphatase Activity for Improved Drought Tolerance. United States Department of Agriculture, dicembre 2012. http://dx.doi.org/10.32747/2012.7613877.bard.
Testo completoAbstract (sommario):
Background to the topic: In previous works we have shown that Arabidopsis and tomato over-expressing H+-pyrophosphatase show increased tolerance to drought imposed by withholding irrigation of young plants in pots (Park et al. 2005). In addition, young tobacco plants over-expressing fatty acid desaturase 3 (OEX-FAD3) also showed increasing tolerance to drought stress (Zhang et al 2005), and similarly OEX-FAD3 young tomato plants (unpublished data from ARO), hence raising the possibility that pyramiding the two could further improve drought tolerance in tomato. Based on these findings the specific objects originally set were: 1. To analyze the impact of pyramiding transgenes for enhanced fatty acid desaturation and for elevated H+-PPase activity on tomato yielding under water deficit stress conditions. 2. To elucidate the biochemical relationship between elevated desaturation of the membrane lipids and the activities of selected vacuolar transporters in the context of drought responses. 3. To explore the S. pennellii introgression lines as alternative genetic sources for drought tolerance related to enhanced fatty acid desaturation and/or H+-PPase activity. 4. Since OEX-FAD3 increases the levels of linolenic acid which is the precursor of various oxylipins including the stress hormone Jasmonate. (JA), study of the effect of this transgene on tolerance to herbivore pests was added as additional goal. The Major conclusions, solutions, and achievements are: (1) The facts that ectopic over-expression of vacuolarH+-PPases (in line OEX-AVP1) does not change the fatty acid profile compared to the parental MoneyMaker (MM) line and that elevated level of FA desaturation (by OEX-FAD3) does not change the activity of either H+-PPase, H+-ATPaseor Ca2+ /H+ antiport, indicate that the observed increased drought tolerance reported before for increase FA desaturation in tobacco plants and increased H+PPase in tomato plants involves different mechanisms. (2) After generating hybrid lines bringing to a common genetic background (i.e. F1 hybrids between line MP-1 and MM) each of the two transgenes separately and the two transgenes together the effect of various drought stress regimes including recovery from a short and longer duration of complete water withhold as well as performance under chronic stresses imposed by reducing water supply to 75-25% of the control irrigation regime could be studied. Under all the tested conditions in Israel, for well established plants grown in 3L pots or larger, none of the transgenic lines exhibited a reproducible significantly better drought tolerance compare to the parental lines. Still, examining the performance of these hybrids under the growth practices followed in the USA is called for. (3) Young seedlings of none of the identified introgression lines including the S. pennellii homologs of two of the H+-PPase genes and one of the FAD7 genes performed better than line M82 upon irrigation withhold. However, differences in the general canopy structures between the IL lines and M82 might mask such differences if existing. (4). Over-expression of FAD3 in the background of line MP-1 was found to confer significant tolerance to three important pest insects in tomato: Bordered Straw (Heliothis peltigera), Egyptian cotton leafworm (Spodoptera littoralis) and Western Flower Thrips (Frankliniella occidentalis). Implications: Although the original hypothesis that pyramiding these two trasgenes could improve drought tolerance was not supported, the unexpected positive impact on herbivore deterring, as well as the changes in dynamics of JA biosynthesis in response to wounding and the profound changes in expression of wound response genes calls for deciphering the exact linolenic acid derived signaling molecule mediating this response. This will further facilitate breeding for herbivore pest and mechanical stress tolerance based on this pathway.
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Sessa, Guido, e Gregory Martin. MAP kinase cascades activated by SlMAPKKKε and their involvement in tomato resistance to bacterial pathogens. United States Department of Agriculture, gennaio 2012. http://dx.doi.org/10.32747/2012.7699834.bard.
Testo completoAbstract (sommario):
The research problem: Pseudomonas syringae pv. tomato (Pst) and Xanthomonas campestrispv. vesicatoria (Xcv) are the causal agents of tomato bacterial speck and spot diseases, respectively. These pathogens colonize the aerial parts of the plant and cause economically important losses to tomato yield worldwide. Control of speck and spot diseases by cultural practices or chemicals is not effective and genetic sources of resistance are very limited. In previous research supported by BARD, by gene expression profiling we identified signaling components involved in resistance to Xcvstrains. Follow up experiments revealed that a tomato gene encoding a MAP kinase kinase kinase (MAPKKKe) is required for resistance to Xcvand Pststrains. Goals: Central goal of this research was to investigate the molecular mechanisms by which MAPKKKεand associated MAP kinase cascades regulate host resistance. Specific objectives were to: 1. Determine whether MAPKKKεplays a broad role in defense signaling in plants; 2. Identify components of MAP kinase cascades acting downstream of MAPKKKε; 3. Determine the role of phosphorylation-related events in the function of MAPKKKε; 4. Isolate proteins directly activated by MAPKKKε-associatedMAPK modules. Our main achievements during this research program are in the following major areas: 1. Characterization of MAPKKKεas a positive regulator of cell death and dissection of downstream MAP kinase cascades (Melech-Bonfil et al., 2010; Melech-Bonfil and Sessa, 2011). The MAPKKKεgene was found to be required for tomato resistance to Xcvand Pstbacterial strains and for hypersensitive response cell death triggered by different R gene/effector gene pairs. In addition, overexpression analysis demonstrated that MAPKKKεis a positive regulator of cell death, whose activity depends on an intact kinase catalytic domain. Epistatic experiments delineated a signaling cascade downstream of MAPKKKεand identified SIPKK as a negative regulator of MAPKKKε-mediated cell death. Finally, genes encoding MAP kinase components downstream of MAPKKKεwere shown to contribute to tomato resistance to Xcv. 2. Identification of tomato proteins that interact with MAPKKKεand play a role in plant immunity (Oh et al., 2011). We identified proteins that interact with MAPKKKε. Among them, the 14-3-3 protein TFT7 was required for cell death mediated by several R proteins. In addition, TFT7 interacted with the MAPKK SlMKK2 and formed homodimersin vivo. Thus, TFT7 is proposed to recruit SlMKK2 and MAPKKK client proteins for efficient signal transfer. 3. Development of a chemical genetic approach to identify substrates of MAPKKKε-activated MAP kinase cascades (Salomon et al., 2009, 2011). This approach is based on engineering the kinase of interest to accept unnatural ATP analogs. For its implementation to identify substrates of MAPKKKε-activated MAP kinase modules, we sensitized the tomato MAP kinase SlMPK3 to ATP analogs and verified its ability to use them as phosphodonors. By using the sensitized SlMPK3 and radiolabeled N6(benzyl)ATP it should be possible to tag direct substrates of this kinase. 4. Development of methods to study immunity triggered by pathogen-associated molecular patterns (PAMPs) in tomato and N. benthamiana plants (Kim et al., 2009; Nguyen et al. 2010). We developed protocols for measuring various PTI-associatedphenotypes, including bacterial populations after pretreatment of leaves with PAMPs, induction of reporter genes, callose deposition at the cell wall, activation of MAP kinases, and a luciferase-based reporter system for use in protoplasts. Scientific and agricultural significance: Our research activities discovered and characterized a signal transduction pathway mediating plant immunity to bacterial pathogens. Increased understanding of molecular mechanisms of immunity will allow them to be manipulated by both molecular breeding and genetic engineering to produce plants with enhanced natural defense against disease. In addition, we successfully developed new biochemical and molecular methods that can be implemented in the study of plant immunity and other aspects of plant biology.