Effects of G, a Growth Regulator from Eucalyptus grandis, on Photosynthesis
AUTOR(ES)
Sharkey, Thomas D.
RESUMO
A growth regulator (G; 4-ethyl-1-hydroxy-4,8,8,10,10 pentamethyl-7,9-dioxo-2,3 dioxyabicyclo (4.4.0) decene-5) from Eucalyptus grandis (Maiden) reduced stomatal conductance and also photosynthetic capacity when fed through the transpiration stream of detached leaves. The concentration of G required for this effect was high (10−4 molar), but the amount of G taken up (dose) was below the level which has previously been found in E. grandis leaves. Similar effects were observed in detached leaves of Xanthium strumarium L. though almost 10 times more G was required. G reduced CO2-dependent O2 evolution from isolated cells of X. strumarium. In spinach (Spinacia oleracea L.) chloroplasts, electron transport through photosystem II was reduced by G. It is proposed that G affects stomatal conductance and photosynthesis by reducing photosystem II activity in both the guard cell chloroplasts and mesophyll cell chloroplasts.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=426331Documentos Relacionados
- Caracterização da madeira de árvores de clones de Eucalyptus grandis, E. saligna e E. grandis x urophylla.
- Identificação de Madeiras de clones de Eucalyptus grandis, Eucalyptus urophylla e do híbrido Eucalyptus urograndis por RMN 13C.
- Identificação de proteínas expressas na região cambial de Eucalyptus grandis, por espectrometria de massa
- Avaliação de algumas propriedades da madeira de Eucalyptus grandis, Eucalyptus saligna e Pinus elliottii
- Caracterização tecnológica de painés de fibras da madeira de eucalipto, Eucalyptus grandis, e de partículas do bagaço do colmo de cana-de-açucar, Saccharum sp