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| Vitória,Angela P.; Lage-Pinto,Frederico; Campaneli,Leonardo B.; Almeida,Marcelo G.; Souza,Cristina M. M.; Rezende,Carlos E.; Azevedo,Ricardo A.; Oliveira,Jurandi G.. |
| The ecophysiological adaptations of water hyacinth (metal hyperaccumulator) under adverse environmental conditions are not yet clearly elucidated. This work evaluated photosynthetic pigments and chlorophyll a fluorescence in water hyacinth plants sampled in different regions (upper, middle and lower) of Paraíba do Sul river (PSR) and Imbé river, Brazil. Additionally Mn, Fe, Zn, Cu, Cr, Pb and Ni were quantified on the shoots and roots. Roots were the preferential site of metal accumulation. Cromium was not detected in the shoots. Iron and Mn were the elements detected in higher concentrations in all samples. Zinc and Cu were detected in higher concentrations in roots of plants from middle and upper PSR, sites of higher anthropogenic activity. The highest... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Pollution; Paraíba do Sul river; Energy dissipation; Photosynthetic pigments; Nonphotochemical quenchings. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000100006 |
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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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| Gonçalves,Marcos C.; Vega,Jorge; Oliveira,Jurandi G.; Gomes,Mara M. A.. |
| Infection by Sugarcane yellow leaf virus (ScYLV) causes severe leaf symptoms in sugarcane (Saccharum spp.) hybrids, which indicate alterations in its photosynthetic apparatus. To gain an overview of the physiological status of infected plants, we evaluated chlorophyll a fluorescence and gas exchange assays, correlating the results with leaf metabolic surveys, i.e., photosynthetic pigments and carbohydrate contents. When compared to healthy plants, infected plants showed a reduction in potential quantum efficiency for photochemistry of photosystem (PSII) and alterations in the filling up of the plastoquinone (PQ) pool. They also showed reduction in the CO2 net exchange rates, probably as a consequence of impaired quantum yield. In addition, reductions were... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Luteoviridae; Carbon metabolism; Photoinhibition; Virus symptoms. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-41582005000100002 |
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