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1.
Artículo en Inglés | MEDLINE | ID: mdl-21869902

RESUMEN

To evaluate the effectiveness of Uncaria tomentosa in minimizing the side effects of chemotherapy and improving the antioxidant status of colorectal cancer (CRC) patients, a randomized clinical trial was conducted. Patients (43) undergoing adjuvant/palliative chemotherapy with 5-Fluorouracil/leucovorin + oxaliplatin (FOLFOX4) were split into two groups: the UT group received chemotherapy plus 300 mg of Uncaria tomentosa daily and the C group received only FOLFOX4 and served as a control. Blood samples were collected before each of the 6 cycles of chemotherapy, and hemograms, oxidative stress, enzymes antioxidants, immunologic parameters, and adverse events were analyzed. The use of 300 mg of Uncaria tomentosa daily during 6 cycles of FOLFOX4 did not change the analyzed parameters, and no toxic effects were observed.

2.
Bull Environ Contam Toxicol ; 86(3): 272-7, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21336859

RESUMEN

Plantlets of Pfaffia glomerata (Spreng.) were exposed in vitro for 30 days to five lead levels (0-400 µM) to analyze the effects on growth and oxidative stress and responses of various antioxidants vis-à-vis lead accumulation. The plantlets showed significant lead accumulation in roots (1,532 µg g(-1) DW) with a low root to shoot lead translocation (ca. 3.6%). The growth of plantlets was negatively affected by various lead treatments, although the level of photosynthetic pigments did not alter significantly in response to any lead treatment. However, plantlets suffered from oxidative stress as suggested by the significant increase in malondialdehyde levels in root (8.48 µmol g(-1) FW) and shoot (3.20 µmol g(-1) FW) tissues with increasing lead treatments. In response to the imposed toxicity, increases in the activities of catalase in root (4.14 ∆E min(-1) mg(-1) protein) and shoot (3.46 ∆E min(-1) mg(-1) protein) and superoxide dismutase in root (345.32 units mg(-1) protein) and shoot (75.26 units mg(-1) protein), respectively, were observed, while the levels of non-protein thiols and ascorbic acid were not affected significantly in either roots or shoots.


Asunto(s)
Amaranthaceae/efectos de los fármacos , Plomo/toxicidad , Contaminantes del Suelo/toxicidad , Amaranthaceae/crecimiento & desarrollo , Amaranthaceae/metabolismo , Brasil , Carotenoides/metabolismo , Catalasa/metabolismo , Clorofila/metabolismo , Relación Dosis-Respuesta a Droga , Tolerancia a Medicamentos , Malondialdehído/metabolismo , Estrés Oxidativo , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Plantas Medicinales/efectos de los fármacos , Plantas Medicinales/crecimiento & desarrollo , Plantas Medicinales/metabolismo , Distribución Aleatoria , Superóxido Dismutasa/metabolismo
3.
Biometals ; 23(2): 295-305, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20063044

RESUMEN

Oxidative stress caused by mercury (Hg) was investigated in Pfaffia glomerata plantlets grown in nutrient solution using sand as substrate. Thirty-day-old acclimated plants were treated for 9 days with four Hg levels (0, 1, 25 and 50 microM) in the substrate. Parameters such as growth, tissue Hg concentration, toxicity indicators (delta-aminolevulinic acid dehidratase, delta-ALA-D, activity), oxidative damage markers (TBARS, lipid peroxidation, and H(2)O(2) concentration) and enzymatic (superoxide dismutase, SOD, catalase, CAT, and ascorbate peroxidase, APX) and non-enzymatic (non-protein thiols, NPSH, ascorbic acid, AsA, and proline concentration) antioxidants were investigated. Tissue Hg concentration increased with Hg levels. Root and shoot fresh weight and delta-ALA-D activity were significantly decreased at 50 microM Hg, and chlorophyll and carotenoid concentration were not affected. Shoot H(2)O(2) concentration increased curvilinearly with Hg levels, whereas lipid peroxidation increased at 25 and 50 microM Hg, respectively, in roots and shoots. SOD activity showed a straight correlation with H(2)O(2) concentration, whereas CAT activity increased only in shoots at 1 and 50 microM Hg. Shoot APX activity was either decreased at 1 microM Hg or increased at 50 lM Hg. Conversely, root APX activity was only increased at 1 microM Hg. In general, AsA, NPSH and proline concentrations increased upon addition of Hg, with the exception of proline in roots, which decreased. These changes in enzymatic and non-enzymatic antioxidants had a significant protective effect on P. glomerata plantlets under mild Hg-stressed conditions.


Asunto(s)
Amaranthaceae/efectos de los fármacos , Amaranthaceae/metabolismo , Antioxidantes/metabolismo , Mercurio/farmacología , Amaranthaceae/anatomía & histología , Ácido Ascórbico/metabolismo , Carotenoides/metabolismo , Clorofila/metabolismo , Peróxido de Hidrógeno/metabolismo , Peroxidación de Lípido , Oxidantes/metabolismo , Estrés Oxidativo , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Brotes de la Planta/efectos de los fármacos , Brotes de la Planta/crecimiento & desarrollo , Brotes de la Planta/metabolismo , Superóxido Dismutasa/metabolismo
4.
Biometals ; 22(5): 779-92, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19330492

RESUMEN

A hydroponic experiment was carried out to characterize the oxidative stress responses of two potato cultivars (Solanum tuberosum L. cvs. Asterix and Macaca) to cadmium (Cd). Plantlets were exposed to four Cd levels (0, 50, 100, 150 and 200 microM) for 7 days. Cd concentration was increased in both roots and shoot. Number of sprouts and roots was not decreased, whereas Cd treatment affected the number of nodal segments. Chlorophyll content and ALA-D activity were decreased in both cultivars, whereas carotenoids content was decreased only in Macaca. Cd caused lipid peroxidation in roots and shoot of both cultivars. Protein oxidation was only verified at the highest Cd level. H(2)O(2) content was increased in roots and shoot of Asterix, and apparently, a compensatory response between roots and shoot of Macaca was observed. SOD activity was inhibited in roots of Asterix at all Cd treatments, whereas in Macaca it was only increased at two highest Cd levels. Shoot SOD activity increased in Asterix and decreased in Macaca. Root CAT activity in Asterix decreased at 100 and 150 microM, whereas in Macaca it decreased only at 50 microM. Shoot CAT activity was decreased in Macaca. Root AsA content in Macaca was not affected, whereas in shoot it was reduced at 100 microM and increased at 200 microM. Cd caused increase in NPSH content in roots and shoot. Our results suggest that Cd induces oxidative stress in both potato cultivars and that of the two cultivars, Asterix showed greater sensitivity to Cd levels.


Asunto(s)
Cadmio/toxicidad , Estrés Oxidativo/efectos de los fármacos , Contaminantes del Suelo/toxicidad , Solanum tuberosum/efectos de los fármacos , Solanum tuberosum/metabolismo , Carotenoides/metabolismo , Catalasa/metabolismo , Peróxido de Hidrógeno/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Oxidación-Reducción/efectos de los fármacos , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Brotes de la Planta/efectos de los fármacos , Brotes de la Planta/crecimiento & desarrollo , Brotes de la Planta/metabolismo , Proteínas/metabolismo , Solanum tuberosum/crecimiento & desarrollo , Superóxido Dismutasa/metabolismo
5.
J Hazard Mater ; 364: 449-467, 2019 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-30384255

RESUMEN

Based on a review of the literature, we have developed a functional conceptual framework of plant metal uptake in relation to plant available metal concentration in the soil. This framework applies to all plant parts and plant available metal levels in soils, and was validated using independent datasets from field surveys and the literature. This is the first framework based on metal transporter kinetic parameters and combining Michaelis-Menten (hyperbolic) kinetics facilitated by the High Affinity Transport System (HATS) for soil concentrations below the transition concentration between transport systems, and linear metal uptake facilitated by the Low Affinity Transport System (LATS) for higher soil available metal concentrations. We propose a new terminology for metal tolerant plants, i.e. metal tolerators, based on this framework. Depending on the plant available metal levels in the soil, tolerator responses to metals can be described best by either Vmax and Km for soil concentrations below the transition concentration between metal transport systems (HATS), or by the slope for greater soil concentrations (LATS). This conceptual framework may be a useful tool for selecting suitable metal tolerators for specific phytoremediation purposes, and may be also applied to non-metal elements or ions.

6.
J Hazard Mater ; 364: 173-181, 2019 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-30366239

RESUMEN

This study investigated tolerance of Australian native grass species Astrebla lappacea, Themeda australis, and Austrostipa scabra and a tree species Acacia harpophylla to different concentrations of arsenic As(V) (13.34-667.36 µM), Cu2+ (0.5-200 µM), Zn2+ (9-500 µM), Mn2+ (8-10240 µM) and Pb2+ (240-9600 µM) in single solutions in germination experiments. Metal/loid tolerance indicators used were maximum germination percentage (Gmax), mean germination time (MGT), radicle and shoot tolerance indexes (RTI & STI). Radicle tolerance index was the most sensitive indicator of metal tolerance in germinating seeds. All native species were highly tolerant to the metal/loids tested, however, they showed different metal toxicity thresholds and levels of tolerance based on RTI as a metal tolerance indicator during germination. Overall, all four species could be classified as metallophytes, confirming their current suitability for and established use in mine site rehabilitation. This work may also serve as a basis for future studies on metal/loid tolerance of other plant species during germination.


Asunto(s)
Acacia/efectos de los fármacos , Arsénico/toxicidad , Germinación/efectos de los fármacos , Poaceae/efectos de los fármacos , Acacia/crecimiento & desarrollo , Australia , Metales Pesados/toxicidad , Brotes de la Planta/efectos de los fármacos , Brotes de la Planta/crecimiento & desarrollo , Poaceae/crecimiento & desarrollo , Semillas/efectos de los fármacos , Semillas/crecimiento & desarrollo
7.
J Mycol Med ; 25(3): 213-7, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26281965

RESUMEN

In the present study, the antifungal activity of essential oils obtained from Origanum vulgare (oregano), Cinnamomum zeylanicum (cinnamon), Lippia graveolens (Mexican oregano), Thymus vulgaris (thyme), Salvia officinalis (sage), Rosmarinus officinalis (rosemary), Ocimum basilicum (basil) and Zingiber officinale (ginger) were assessed against Candida glabrata isolates. One group contained 30 fluconazole-susceptible C. glabrata isolates, and the second group contained fluconazole-resistant isolates derived from the first group after the in vitro induction of fluconazole-resistance, for a total of 60 tested isolates. The broth microdilution methodology was used. Concentrations of 50µg/mL, 100µg/mL, 200µg/mL, 400µg/mL, 800µg/mL, 1600µg/mL and 3200µg/mL of the essential oils were used, and the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) were determined. Thyme, sage, rosemary, basil and ginger essential oils showed no antifungal activity at the tested concentrations. Antimicrobial activity less than or equal to 3200µg/mL was observed for oregano, Mexican oregano and cinnamon essential oils. Both the oregano and Mexican oregano essential oils showed high levels of antifungal activity against the fluconazole-susceptible C. glabrata group, whereas the cinnamon essential oil showed the best antifungal activity against the fluconazole-resistant C. glabrata isolates.


Asunto(s)
Candida glabrata/efectos de los fármacos , Condimentos , Fluconazol/uso terapéutico , Aceites Volátiles/farmacología , Antifúngicos/farmacología , Candida glabrata/crecimiento & desarrollo , Farmacorresistencia Microbiana/efectos de los fármacos , Humanos , Pruebas de Sensibilidad Microbiana , Extractos Vegetales/farmacología , Aceites de Plantas/farmacología
8.
Rev Esc Enferm USP ; 33(3): 236-49, 1999 Sep.
Artículo en Portugués | MEDLINE | ID: mdl-10889758

RESUMEN

The aim of this study was evaluate the utilization of tools for pain perception assessment in 41 hospitalized pre-school children submitted to painful procedures: care of wounds or blood extraction. The utilized tools were the faces scale, behavioral indicators and words which describe the pain. Most of the pre-schoolers understood and correctly answered to the faces scale, which can be noticed by the crescent movement 0 (no pain) 4 (maximum pain) during the choice of faces before and after the painful procedure. Crying, immortality and forehead wrinkling were the predominant behavioral indicators, intensified during the procedure. Pre-schoolers verbalizations about their pain showed up to be concrete terms or evaluative-indicative nature, resulting in variable or weakly precise concepts.


Asunto(s)
Actitud Frente a la Salud , Niño Hospitalizado/psicología , Dimensión del Dolor/métodos , Dimensión del Dolor/psicología , Dolor/diagnóstico , Dolor/psicología , Factores de Edad , Recolección de Muestras de Sangre/efectos adversos , Niño , Conducta Infantil , Preescolar , Expresión Facial , Femenino , Humanos , Masculino , Dolor/etiología , Dolor/enfermería , Psicología Infantil , Reproducibilidad de los Resultados , Heridas y Lesiones/complicaciones
9.
Rev Esc Enferm USP ; 28(1): 27-39, 1994 Apr.
Artículo en Portugués | MEDLINE | ID: mdl-7569237

RESUMEN

The purpose of this study is to discuss the utilization of informatics in nursing and the construction of computerized data bases by nursing professionals that have no previous experience with computers. Three data bases developed during the pos graduate nursing course are described.


Asunto(s)
Bases de Datos Factuales , Enfermería , Capacitación de Usuario de Computador , Educación de Postgrado en Enfermería , Humanos
10.
J Hazard Mater ; 248-249: 442-50, 2013 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-23416872

RESUMEN

Metal contamination of landscapes as a result of mining and other industrial activities is a pervasive problem worldwide. Metal contaminated soils often lack effective vegetation cover and are prone to contaminant leaching and dispersion through erosion, leading to contamination of the environment. Metal-binding hydrogel particle amendments could ameliorate mine wastes prior to planting and enhance seedling emergence. In this study, micron-size thiol functional cross-linked acrylamide polymer hydrogel particles (X3) were synthesised and tested in laboratory-scale experiments on phytotoxic mine wastes to determine their capacity to: (i) increase substrate water holding capacity (WHC); (ii) reduce metal availability to plants to below the phytotoxicity threshold; and (iii) enhance germination characteristics and early radicle development of two Australian metallophyte grasses under limiting and non-limiting water conditions. Addition of X3 to mine wastes significantly increased their WHC and lowered toxic soluble metal concentrations in mine waste leachates. Germination percentages and radicle elongation of both grasses in wastes were significantly increased. Highest germination percentages and greater radicle development recorded in X3 amended wastes under water limited conditions suggests that X3 was able to ameliorate metal toxicity to radicles, and provide moisture, which improved the imbibition and consequent germination of the seeds.


Asunto(s)
Hidrogeles/farmacología , Poaceae/efectos de los fármacos , Acrilamidas/química , Germinación/efectos de los fármacos , Hidrogeles/química , Residuos Industriales , Metales/química , Minería , Tamaño de la Partícula , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/crecimiento & desarrollo , Poaceae/crecimiento & desarrollo , Agua/química
11.
J Hazard Mater ; 248-249: 424-34, 2013 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-23416487

RESUMEN

Soil contaminants are potentially a major threat to human and ecosystem health and sustainable production of food and energy where mineral processing wastes are discharged into the environment. In extreme conditions, metal concentrations in wastes often exceed even the metal tolerance thresholds of metallophytes (metal-tolerant plants) and sites remain barren with high risks of contaminant leaching and dispersion into the environment via erosion. A novel soil amendment based on micron-size thiol functional cross-linked acrylamide polymer hydrogel particles (X3) binds toxic soluble metals irreversibly and significantly reduces their concentrations in the soil solution to below the phytotoxicity thresholds. X3 mixed into the top 50mm of phytotoxic mine waste materials in pots in glasshouse conditions reduced total soluble concentrations of toxic contaminants by 90.3-98.7% in waste rock, and 88.6-96.4% in tailings immediately after application. After 61 days, quality of unamended bottom layer of X3-treated pots was also significantly improved in both wastes. Combination of X3 and metallophytes was more efficient at improving soil solution quality than X3 alone. Addition of X3 to substrates increased substrate water retention and water availability to plants by up to 108% and 98% for waste rock and tailings respectively. Soil quality improvement by X3 allowed successful early establishment of the native metallophyte grass Astrebla lappacea on both wastes where plants failed to establish otherwise.


Asunto(s)
Hidrogeles/química , Metales/química , Contaminantes del Suelo/química , Acrilamida/química , Restauración y Remediación Ambiental , Germinación/efectos de los fármacos , Residuos Industriales , Metales/toxicidad , Minería , Brotes de la Planta/efectos de los fármacos , Brotes de la Planta/crecimiento & desarrollo , Poaceae/efectos de los fármacos , Poaceae/fisiología , Plantones/efectos de los fármacos , Plantones/crecimiento & desarrollo , Contaminantes del Suelo/toxicidad
12.
Meat Sci ; 93(1): 98-104, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22938774

RESUMEN

Physicochemical properties and fatty acid profiles of meat from Bos indicus, Bos taurus and crossbred B. taurus×B. indicus bullocks (n=216), finished on pasture or grain, were used to estimate the effects of heterosis. Meat quality and fatty acid profiles generally benefited with crossbreeding, but the advantages from heterosis differed among finishing systems. The Warner-Bratzler shear-force in fresh and aged meat was reduced due to heterosis in pasture-finishing, but the effect was minor under grain-finishing. With pasture-finishing, heterosis caused an increase of 5% in CLA concentration, but few other changes in fatty acid profiles. In grain-finishing, heterosis caused a reduction in intramuscular fat and cholesterol, increased amounts of PUFA, n-6 fatty acids and PUFA/SFA ratio, and a decline in atherogenic index. The Δ(9) desaturase estimated activity in crossbreds showed a behavior close to B. indicus, suggesting the existence of few loci and a dominance genetic effect on enzymes involved in fatty acid synthesis and metabolism.


Asunto(s)
Alimentación Animal , Cruzamiento , Dieta , Grasas de la Dieta/metabolismo , Ácidos Grasos/genética , Vigor Híbrido , Carne/análisis , Crianza de Animales Domésticos/métodos , Animales , Aterosclerosis/inducido químicamente , Bovinos , Colesterol en la Dieta/metabolismo , Grano Comestible , Ácidos Grasos/metabolismo , Ácidos Grasos Insaturados/genética , Ácidos Grasos Insaturados/metabolismo , Sitios Genéticos , Ácidos Linoleicos Conjugados/genética , Ácidos Linoleicos Conjugados/metabolismo , Carne/normas , Músculo Esquelético/metabolismo , Poaceae , Especificidad de la Especie , Estearoil-CoA Desaturasa/genética , Estearoil-CoA Desaturasa/metabolismo , Estrés Mecánico
14.
J Hazard Mater ; 190(1-3): 772-9, 2011 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-21514726

RESUMEN

Combining metal-binding particles and metal-tolerant plants (metallophytes) offers a promising new approach for rehabilitation of heavy metal contaminated sites. Three types of hydrogel metal-binding polymer particles were synthesized and their effects on metal concentrations tested in vitro using metal ion solutions. The most effective of the tested polymers was a micron-sized thiol functional cross-linked acrylamide polymer which reduced the available solution concentrations of Pb(2+) (9.65 mM), Cu(2+) (4mM) and Zn(2+) (10mM) by 86.5%, 75.5% and 63.8%, respectively, and was able to store water up to 608% of its dry mass. This polymer was not toxic to seed germination. In deionised water, it enhanced seed germination, and at otherwise phytotoxic Pb(2+) (9.65 mM) and Zn(2+) (10mM) concentrations, it allowed normal germination and root elongation of the metallophyte grass Astrebla lappacea. We conclude that the polymer has the potential to facilitate restoration of heavy metal contaminated lands by reducing the concentration of metal cations in the soil solution and improving germination rates through reduced toxicity and enhanced plant water relations.


Asunto(s)
Restauración y Remediación Ambiental , Germinación/efectos de los fármacos , Metales Pesados/toxicidad , Poaceae/efectos de los fármacos , Polímeros/farmacología , Acrilamidas/farmacología , Plomo/farmacocinética , Plomo/toxicidad , Metales Pesados/farmacocinética , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/crecimiento & desarrollo , Poaceae/metabolismo , Poaceae/fisiología , Polímeros/química , Contaminantes del Suelo/farmacocinética , Agua/metabolismo , Zinc/farmacocinética , Zinc/toxicidad
15.
J Anim Sci ; 89(1): 221-32, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21178183

RESUMEN

A study was conducted to characterize lipid profiles in the M. longissimus thoracis of commercial Brazilian beef and to assess how those profiles are influenced by finishing system, genetic group, and their interaction. Intramuscular fat (IMF) and fatty acid (FA) profiles were determined in 160 bulls of the Bos taurus (n = 75) and Bos indicus (n = 85) genetic groups, finished on pasture (n = 46) or with grain supplementation (n = 114) and slaughtered in a commercial abattoir. Finishing system had a major impact on the deposition of IMF, as well as on the concentration of SFA, PUFA, and their ratio, but genetic groups showed important differences in the ability to convert SFA into cis-9 MUFA and to convert 16:0 into 18:0. When compared with pasture-finished animals, those finished with grain had greater content of IMF and SFA (P < 0.01), similar amounts of MUFA (P > 0.05), and about one-half the amount of PUFA (P < 0.01). Except for MUFA, differences in FA profiles among finishing systems were mostly mediated through their effect on IMF, even though the relationship of IMF with groups of FA differed among finishing systems. Under grain finishing, B. taurus had less SFA and greater MUFA than B. indicus (P < 0.01), but no differences were observed in PUFA (P > 0.05). With pasture-finishing, no differences were observed among the 2 genetic groups in SFA and MUFA (P > 0.05), but PUFA were decreased in B. taurus (P < 0.01). When genetic groups were compared in grain-finishing, B. taurus had a decreased ability for elongation and B. indicus had a decreased aptitude for desaturation of FA. On the other hand, with pasture-finishing a greater deposition of intermediate FA from ruminal biohydrogenation was observed in B. indicus than in B. taurus. Overall, FA profiles were affected more by finishing system in B. indicus than in B. taurus.


Asunto(s)
Composición Corporal/genética , Dieta/veterinaria , Ácidos Grasos/metabolismo , Tejido Adiposo/química , Envejecimiento , Alimentación Animal , Crianza de Animales Domésticos , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Composición Corporal/fisiología , Bovinos , Grano Comestible , Ácidos Grasos/química , Masculino
16.
Rev. bras. plantas med ; Rev. bras. plantas med;17(2): 239-245, Apr-Jun/2015. tab, graf
Artículo en Inglés | LILACS | ID: lil-746135

RESUMEN

ABSTRACT: The objective of this study was to develop an in vitro protocol for the micropropagation of Pluchea sagittalis (Lam.) Cabrera. Plants were regenerated in vitro from stem segments. The procedure employed includes: 1) surface sterilization of shoots by immersion in 70% ethanol for 10 s followed by 1.0% NaOCl for 10 min, and subsequent immersion in 0.05% HgCl2 for 3 min and two washes with sterile distilled water; 2) induction of root and shoot by culture on hormone-free Murashige and Skoog medium (MS); 3) acclimatization of 60 day-old-plantlets in soil under ex vitro conditions. Minimum contamination was observed for apical shoot explants (10%). However, independently of the explant position in the stem, all explants regenerated new shoots. Various successive cultivations from stem explants every 60 days during more than 1 year have been shown to be a suitable method to propagate P. sagittalis in vitro. Low salt concentration (25% of the normal concentration) in the medium promoted greater growth of plantlets because the plants had a higher number of roots and longer roots in such an environment. Our protocol for the micropropagation of P. sagittalis can be accomplished as a two-step procedure within a short period of time (two months) before transplanting.


RESUMO: O Objetivo deste estudo foi desenvolver um protocolo para a micropropagação in vitro da Pluchea sagittalis (Lam.) Cabrera. Plantas foram regeneradas in vitro a partir de segmentos de ramo. O procedimento empregado incluiu: 1) esterilização da superfície de ramos pela imersão em etanol 70% por 10 s seguida pela de NaOCl 1.0% por 10 min e, subsequentemente, em HgCl2 0.05% por 3 min e duas lavagens em água destilada e esterilizada; 2) indução de raízes e parte aérea pelo cultivo em meio Murashige & Skoog (MS) isento de hormônio; 3) aclimatização de plantas com 60 dias de idade em solo sob condições ex vitro. Contaminação mínima foi observada em explantes caulinares do ápice (10%). Entretanto, independentemente da posição do segmento no caule, todos explantes regeneraram novos ramos. Vários cultivos sucessivos a cada 60 dias durante mais de um ano tem mostrado ser um método adequado para a propagação in vitro de P. sagittalis. A baixa concentração de sais no meio (25% da concentração normal) promoveu maior crescimento das plântulas devido às mesmas apresentarem maior número e comprimento de raízes. O protocolo para a micropropagação da P. sagittalis pode ser executado em procedimento de duas etapas dentro de um período de tempo curto (dois meses) antes do transplantio.


Asunto(s)
Asteraceae/clasificación , Sales (Química)/farmacología , Técnicas In Vitro/instrumentación , Productos Agrícolas
17.
J Hazard Mater ; 172(1): 479-84, 2009 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-19625122

RESUMEN

The present study was designed to study the process of stress adaptation in roots and shoot of Zea mays seedlings grown under hydroponic conditions during exposure to lead (Pb) (0-200 microM) for 1-7 d. The alterations in growth and in the level of various biochemical parameters were accessed vis-à-vis Pb accumulation. The accumulation of Pb increased in a concentration-duration-dependent manner, however its translocation from root to shoot was low. At the same time, the level of malondialdehyde (MDA) increased with increasing Pb concentration. However, growth parameters, such as dry weight and root length did not show a significant decline to any of the Pb concentrations. In addition, the level of photosynthetic pigments decreased only upon exposure to high Pb concentrations. These results suggested an alleviation of the stress that was presumably being achieved by antioxidants viz., superoxide dismutase (SOD) and catalase (CAT) as well as ascorbic acid (AsA), which increased linearly with increasing Pb levels and exposure time. However, the level of non-protein thiols (NP-SH) in roots, in general, showed a decline beyond 4d that could be attributed to their consumption for the purpose of Pb detoxification. In conclusion, Zea mays can be used as an indicator species for Pb, and the various antioxidants might play a key role in the detoxification of Pb induced toxic effects.


Asunto(s)
Antioxidantes/metabolismo , Hidroponía/métodos , Plomo/toxicidad , Plantones/metabolismo , Zea mays/metabolismo , Adsorción , Ácido Ascórbico/química , Catalasa/química , Catalasa/metabolismo , Clorofila/química , Plomo/química , Peroxidación de Lípido , Malondialdehído/química , Modelos Estadísticos , Porfobilinógeno Sintasa/química , Plantones/efectos de los fármacos , Compuestos de Sulfhidrilo/química , Superóxido Dismutasa/metabolismo
18.
Ann Bot ; 95(5): 853-61, 2005 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15701662

RESUMEN

BACKGROUND AND AIMS: Despite its high capacity to take up nitrate from the soil, winter oilseed rape (Brassica napus) is characterized by a very low N recovery in the reproductive tissues under field conditions. A significant part of the N taken up is lost to the soil in dead leaves during the growth cycle. An accurate description of N dynamics at the whole plant level in each compartment under field conditions should lead to a better understanding of N allocation in B. napus and improvements in the nitrogen harvest index. METHODS: An experiment was conducted in field conditions using sequential weekly 15N labelling to follow N uptake, partitioning and mobilization. Nitrogen labelling (2.5 kg N ha(-1); 10 % excess) was analysed weekly (from stem extension to harvest) to distinguish between uptake of new N (labelled) and mobilized N (unlabelled) in the different plant components. KEY RESULTS AND CONCLUSIONS: N requirements for seed filling were satisfied mainly by N mobilized from vegetative parts (about 73 % of the total N in pods). Determination of the endogenous N flow showed that there was net transfer of N to the pods by leaves (36 %), stem (34 %), inflorescences (22 %) and taproot (8 %). Precise study of N flow from leaves at different nodes revealed the existence of two main groups of leaves in terms of their apparent capacity to mobilize N; 30-60 % and 70-80 % of peak N content occurring during flowering and pod filling, respectively. Moreover, the latter group was found to be the main source of endogenous N from leaves. The mobilization of endogenous N from these leaves was prolonged and concomitant with N accumulation in the pods. A complex pattern of N mobilization from the leaves, to vegetative or reproductive tissues, was revealed. These results will be used to model N partitioning during the growth cycle.


Asunto(s)
Brassica napus/metabolismo , Nitrógeno/metabolismo , Tallos de la Planta/metabolismo , Transporte Biológico , Biomasa , Marcaje Isotópico , Hojas de la Planta/metabolismo , Tallos de la Planta/crecimiento & desarrollo , Temperatura
19.
Ann Bot ; 95(7): 1187-98, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15802311

RESUMEN

BACKGROUND AND AIMS: Oilseed rape (Brassica napus) has often been used as a catch crop to deal with the issue of N leaching, but for this to be effective, prediction of the crop's N uptake capability and N partitioning is required. The aim of this work was to build a compartmental model of N dynamics in oilseed rape, based on the kinetic description of N uptake, partitioning and mobilization in each organ. MODEL: In this study, logistic and exponential equations were fitted to the N relations of each compartment, especially the leaf at each node. Data previously obtained from an 15N-labelling field experiment was used to quantify the partitioning of total N content, the allocation of N taken up and subsequent changes in the sink/source status for endogenous N in each tissue throughout the growth cycle. KEY RESULTS AND CONCLUSIONS: This modelling approach provides a unique tool for the quantitative estimation of cycling of endogenous N in relation to changes in N uptake at the whole-plant level. Furthermore, as oilseed rape is known to release large amounts of N to the soil during spring through leaf loss, this model was used to identify potential methods for improving the N harvest index of the crop. Simulations showed that N content or yield could be improved by 15% by optimizing N transfer from vegetative to reproductive tissues and by reducing the residual %N (DW) in abscised leaves.


Asunto(s)
Brassica napus/metabolismo , Nitrógeno/metabolismo , Transporte Biológico Activo , Simulación por Computador , Modelos Biológicos , Isótopos de Nitrógeno , Tallos de la Planta , Factores de Tiempo
20.
J Exp Bot ; 52(361): 1655-63, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11479330

RESUMEN

Oilseed rape (Brassica napus L.) is commonly grown for oil or bio-fuel production, while the seed residues can be used for animal feed. It can also be grown as a catch crop because of its efficiency in extracting mineral N from the soil profile. However, the N harvest index is usually low, due in part to a low ability to remobilize N from leaves and to the fall of N-rich leaves which allows a significant amount of N to return to the environment. In order to understand how N filling of pods occurs, experiments were undertaken to quantify N flows within the plant by (15)N labelling and to follow the changes in soluble protein profiles of tissues presumed to store and subsequently to remobilize N. Whereas N uptake increased as a function of growth, N uptake capacity decreased at flowering to a non-significant level during pod filling. However, large amounts of endogenous N were transferred from the leaves to the stems and to taproots which acted as a buffering storage compartment later used to supply the reproductive tissue. About 15% of the total N cycling through the plant were lost through leaf fall and 48%, nearly all of which had been remobilized from vegetative tissues, were finally recovered in the mature pods. SDS-PAGE analysis revealed that large amounts of a 23 kDa polypeptide accumulated in the taproots during flowering and was later fully hydrolysed. Its putative function of storage protein is further supported by the fact that when plants were grown at lower temperature, both flowering, its accumulation and further mobilization were delayed. The overall results are discussed in relation to plant strategies which optimize N cycling to reproductive sinks by means of buffering vegetative tissues such as stems and taproots.


Asunto(s)
Brassica/metabolismo , Nitrógeno/metabolismo , Proteínas de Plantas/metabolismo , Transporte Biológico , Brassica/crecimiento & desarrollo , Frutas/crecimiento & desarrollo , Frutas/metabolismo , Marcaje Isotópico , Cinética , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Tallos de la Planta/crecimiento & desarrollo , Tallos de la Planta/metabolismo , Reproducción , Semillas/crecimiento & desarrollo , Semillas/metabolismo , Temperatura
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