ISSN:
1432-2048
Keywords:
Leaves, high- and low-light
;
Light and photophosphorylation
;
Photophosphorylation, cyclic and non-cyclic
;
Sinapis
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Noncyclic electron transport to ferricyanide and photophosphorylation as well as the methylviologen mediated aerobic and anaerobic photophosphorylation with dichlorophenolindophenol-ascorbate as the electron donor of photosystem I were measured during the development of high-light and low-light adapted leaves of Sinapis alba. Anaerobic methylviologen-catalyzed phosphorylation is more than twice as high as aerobic phosphorylation. The difference between the rates of aerobic and anaerobic phosphorylation is sensitive to dibromothymoquinone. Thus, under anaerobic conditions, methylviologen mediates a cyclic phosphorylation including plastoquinone. All photochemical activities of high-light chloroplasts are about twice as high as that of low-light chloroplasts and show a permanent decline with increasing plant age. The lower activities of low-light chloroplasts correlate with a decrease of electron transport components, such as cytochrome f. This indicates that the number of electron transport chains is decreased under low-light conditions and more chlorophyll molecules interact with one electrontransport chain.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00384247
Permalink
