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| Registros recuperados: 360 | |
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| Olivares,Elizabeth. |
| Tithonia diversifolia, a ruderal weedy species utilized in agroforestry, is widely distributed in the tropics, often being found in wasteland, margins of polluted city rivers and roadsides. The objective of this study was to compare plants sampled at a light and heavy traffic roadside for metal concentration and foliar compounds which may be related to senescence and/or detoxification of metals. The field survey was followed by an experiment in pots of Pb-acetate-supplemented soil to verify if the same response is obtained under controlled conditions with regard to Pb. The concentration of Pb in leaves and roots of plants sampled at a heavy traffic roadside was higher than in samples from a light traffic site. The content of Cr, Al, Fe, Cu and Ni was also... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Asteraceae; Metals; Mexican sunflower; Phenols; Pollution; Weeds. |
| Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202003000300004 |
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| Sharma,Priyanka; Bhardwaj,Renu; Arora,Nitika; Arora,Hardesh Kumar. |
| The present work was undertaken to study the effects of 28-homobrassinolide on growth, zinc metal uptake, antioxidative enzyme [guaiacol peroxidase (EC 1.11.1.7), catalase (EC 1.11.1.6), glutathione reductase (EC 1.6.4.2), ascorbate peroxidase (EC 1.11.1.11), superoxide dismutase (EC 1.15.1.1)] activities and protein content in 7-d-old seedlings of Brassica juncea L. treated with Zn metal at different concentrations. 28-homobrassinolide at 10-9 M concentration lowered Zn uptake and bioconcentration factor. Different concentrations of Zn-metal treatment alone decreased the enzyme activities and protein concentration of seedlings. However, pre-sowing treatments of 28homobrassinolide lowered the uptake of metal and enhanced the activities of enzymes and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Antioxidative enzymes; 28-homobrassinolide; Brassinosteroids; Zinc toxicity. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000300004 |
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| Silva,Anandra S.; Oliveira,Jurandi G.; Cunha,Maura da; Vitória,Angela P.. |
| The photosynthetic dynamics of the tropical pioneer species, Byrsonima sericea DC., were studied during the regeneration process of a native forest by evaluating ecophysiological (gas exchange, chlorophyll a fluorescence and photosynthetic pigment contents) and anatomical parameters of plants in sunny and shady environments. Ecophysiological evaluations were carried out monthly for one year, encompassing both a dry and a rainy season. Byrsonima sericea DC. presents anatomical plasticity that enables it to establish in environments with contrasting light regimes. In sunny conditions, it produced a thicker leaf (about 420 mm) and flat adaxial epidermis, whilst in the shade, leaves had a thinner convex adaxial epidermis (about 395 mm). No differences were... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Atlantic forest species; Photosynthetic adaptation; Leaf anatomy; Sun overexposure; Shaded plants. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000400004 |
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| DaMatta,Fábio M.; Ronchi,Cláudio P.; Maestri,Moacyr; Barros,Raimundo S.. |
| After oil, coffee is the most valuable traded commodity worldwide. In this review we highlighted some aspects of coffee growth and development in addition to focusing our attention on recent advances on the (eco)physiology of production in both Coffea arabica and C. canephora, which together account for 99% of the world coffee bean production. This review is organized into sections dealing with (i) climatic factors and environmental requirements, (ii) root and shoot growth, (iii) blossoming synchronisation, fruiting and cup quality, (iv) competition between vegetative and reproductive growth and branch die-back, (v) photosynthesis and crop yield, (vi) physiological components of crop yield, (vii) shading and agroforestry systems, and (viii) high-density... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Arabica conilon and robusta coffee beverage quality density planting die-back flowering photosynthesis; Shading. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202007000400014 |
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| Borghetti,Fabian; Noda,Fabio Nakamura; Sá,Cezar Martins de. |
| Freshly harvested sunflower seeds (Helianthus annuus L., Asteraceae) present physiological dormancy localized at the embrionary axis which prevents germination at low temperatures. However, dormant embryos reach about 100 % germination when incubated with the phytohormone ethylene during imbibition. To examine whether proteinase activities are implicated in the breaking of dormancy by ethylene, dormant embryos were treated with the proteinase inhibitors leupeptin, E64 and the proteasome specific inhibitor clasto-lactacystin ß-lactone (lactacystin). A few embryos (< 10 %) germinated at 10 ºC in absence of ethylene but ethylene-treated embryos reached high germinability (~90 %) in the presence of leupeptin, E64, water and DMSO. On the other hand,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Helianthus annuus; Dormancy; Ethylene; Lactacystin; Proteasome. |
| Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202002000200007 |
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| García-Hernández,Edith del R.; López,Gladys I. Cassab. |
| Boron (B) is an essential micronutrient for the survival of vascular plants. The most severe effect derived from a deficiency of B is the alteration of cell wall biogenesis and pollen germination. We investigated pollen of plant species that require B for germination (Zea may L. and Nicotiana tabacum L.), as well as those that can germinate without B (Pinus sp, Lilum longiflorum, Impatiens sp.). In both groups, B addition in the growth medium increased the length of the pollen tube after germination. Hydroxyproline Rich Glycoproteins (HRGPs) are the most abundant cell wall structural proteins of dicotyledonous plants and the sexual tissues of monocotyledonous plants. Here, we show that maize pollen accumulated a significant pool of hydroxyproline (Hyp) and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cell wall; HRGPs; Hydroxyproline; Pollen tube. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000400005 |
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| Pandey,Nalini; Pathak,Girish C.; Pandey,Dharmendra K.; Pandey,Ritu. |
| Exposure of 10-d-old spinach (Spinacea oleracea L.) plants to excess (500 µM) concentrations of Co, Ni, Cu, Zn and Cd in sand culture inhibited growth, induced toxicity symptoms, oxidative damage and changes in the antioxidant defense system. The severity of the metal-induced effects varied with the metals and the duration of exposure to excess supply of the metals. Each metal induced chlorosis. In addition, excess Co, Ni and Cd also produced metal specific toxic effects. Excess supply of each metal caused lipid peroxidation (TBARS). Their effectiveness in producing oxidative damage was in the order: Ni > Co > Cd > Cu >Zn. Of all the metals, Ni was also most effective in lowering the concentration of the chloroplast pigments (Chl, Car). While... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ascorbate-glutathione cycle; Heavy metal exposure; Spinacia oleracea L. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000200003 |
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| Fariduddin,Qazi; Mir,Bilal Ahmad; Ahmad,Aqil. |
| The present study was conducted to evaluate salt tolerance in seven different pure-line cultivars of tomato (Solanum lycopersicum L.) viz. K-21, Pusa Ruby, Pusa Gorav, Hera research, Selection N5, PKM-1 and S-22 based on several physiological and biochemical traits. Seedlings were transplanted to the pots, being exposed to different salinity levels in the form of NaCl (0, 50, 100, or 150 mM) at a 35-day stage of growth for six days. The plants exposed to salt stress presented a significant decline in growth, photosynthetic parameters, maximum quantum yield of PSII and leaf water relations, which were drastically reduced in variety S-22, while variety K-21 was the least affected. Electrolyte leakage was superior in proportion to an increase in salinity... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Salt tolerance; Solanum lycopersicum L.; Physiological and biochemical traits; Screening. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202012000400007 |
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| Mengarda,Liana H. G.; Souza,Rogério L. F. de; Campostrini,Eliemar; Reis,Fabrício O.; Vendrame,Wagner A.; Cuzzuol,Geraldo R. F.. |
| The ecophysiological behavior of brazilwood (Caesalpinia echinata Lam.) plants was evaluated as affected by light quantity and quality. Nine-month-old plants were cultivated under 0%, 50%, and 80% artificial shading, and natural shading imposed by a closed canopy for a period of 392 days. At the end of that period growth parameters were measured, including relative growth rate (RGR), net assimilation rate (NAR), leaf area ratio (LAR), specific leaf mass (SLM) and root:shoot ratio (R:S). Higher leaf area, dry mass and RGR were obtained under 50% artificial shade. Under full sunlight (0% shade), growth was satisfactory showing higher R:S and SLM. Growth was inhibited under 80% artificial and natural shading indicating that C. echinata is not... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chlorophyll fluorescence; Gas exchange; Growth; Light stress; Shade; Tropical tree. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000100007 |
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