ISSN:
1399-3054
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
Changes in the extent of P700 oxidation (P700+) were investigated after chilling of barley, rice, pumpkin, and cucumber leaf segments at 4°C for 1 h under light with various photon flux densities. At 50 µmol photons m−2 s−1, the decrease in P700+ was observed only in cucumber, but at 150 µmol photons m−2 s−1, it was found in all plants except barley, revealing their expected chilling sensitivities. However, the decrease in P700+ by this short-term chilling was reversible in the presence of 3-(3′,4′-dichlorophenyl)-1,1-dimethylurea or methyl viologen, and it did not show any causal relationship with the decrease in the electron transfer rate nor with the down-regulation of photosystem II through the accumulation of zeaxanthin and the development of non-photochemical quenching. These results led to the suggestion that photosystem I (PSI) acceptor side limitation is a prerequisite for the decrease of P700+. Furthermore, PSI acceptor side limitation could be mainly due to limitation of electron-sink pathways such as CO2 assimilation and ascorbate–glutathione cycle, because treatment with glycolaldehyde which inhibits the former pathway, and with KCN which inhibits both pathways, decreased P700+ by 20–30% in barley leaves after chilling in the light.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1399-3054.2005.00443.x
Permalink