Abstract
Abstract A computer model describing the “Z-scheme” of photosynthetic electron transport in terms of reduction and oxydation of coupled redox pools was built up. Starting from a certain initial state corresponding to the dark adapted state of the photosynthetic system the reduction and reoxidation levels of the pools were calculated during adaptation of the system to a steady state in the light. The changes of calculated redox levels were compared with experimental results of fluorescence and oxygen evolution induction curves. It is shown that the transients in prompt fluorescence and oxygen evolution can be described by reduction and reoxidation of the primary electron acceptor pool and the electron donor pool of photosystem II due to reduction and oxidation of the other pools during adaptation to light. The first depression D in the fluorescence induction curve is explained by the existence of a redox pool X between the primary electron acceptor pool Q of photosystem II and plastoquinone. It is shown that DCMU blocks the electron flow between Q and X. Furthermore, it is shown that the inhibitor DBMIB probably not only blocks the electron flow but also causes a successive disconnection of the plastoquinone pool from the electron transport chain.
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have