Data/hora: 02/06/2024 03:30:36

Provedor de dados: | Brazilian Journal of Plant Physiology
País: | Brazil
Título: | Photosynthetic capacity of three phytoplanktonic species measured by a pulse amplitude fluorometric method
Autores: | Figueredo,Cleber Cunha; Giani,Alessandra; Lemos Filho,José Pires.
Data: | 2009-01-01
Ano: | 2009
Palavras-chave: | Chlorophytes photosynthesis; Electron Transport Rate; Phytoplankton.
Resumo: | During photosynthesis, absorbed energy that is not used in photochemical reactions dissipates as fluorescence. Fluorescence provides important information on the physiological conditions of the studied organisms and its measurement is widely used by plant physiologists and can be valuable in phytoplankton studies. We describe a method adapting a plant fluorometric equipment to measure the photosynthetic capacity of microalgae. Unialgal cultures of three planktonic chlorophytes were exposed to 3(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), an inhibitor of photosystem II, at concentrations of 0.1, 1.0 and 10.0 µmol.L-1. Estimates were made of photosynthetic parameters, including operational and potential photosystem II quantum yield and electron transport rate between photosystems, using algal cells concentrated on glass-fiber filters. The technique allowed reliable measurements of fluorescence, and detection of distinct levels of inhibition. Physiological or morphological characteristics of the selected species might provide an explanation for the observed results: differences on the surface/volume ratio of the cells and colony morphology, for example, were associated with contrasting resistance to the toxicant. To characterize inhibition on phytoplanktonic photosynthesis, we suggest operational quantum yield and electron transport rate as best parameters, once they were more sensitive to the DCMU toxicity.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202009000300001
Editor: | Brazilian Journal of Plant Physiology
Relação: | 10.1590/S1677-04202009000300001
Formato: | text/html
Fonte: | Brazilian Journal of Plant Physiology  v.21 n.3 2009
Fonte: | info:eu-repo/semantics/openAccess