Photoinactivation of the electron transfer through photosystem 2 as studied by time resolved flash absorption spectroscopy

Title:

Photoinactivation of the electron transfer through photosystem 2 as studied by time resolved flash absorption spectroscopy

Creator:

Eckert, H.-J., Liu, B., Eichler, H. J., and Renger, G.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:7e6dbe4f-242e-4461-9108-4a3dc1afe1ec
uuid:7e6dbe4f-242e-4461-9108-4a3dc1afe1ec
urnnbn:urn:nbn:cz:aba007-000fbm

Type:

model:internalpart and TEXT

Format:

print

Description:

Primary events in the photoinactivation of photosystem (PS) 2 membrane fragments by low and high "visible light" irradiance (17 to 1 700 W m'2) and UV-B irradiation (90 W m'2) were analyzed by measuiing flash-induced absorption changes at 830 nm that reflect transient formation of P680+ and Pheo*. Following results were obtained: (7) Irradiation with "visible light" under aerobic conditions affects the PS 2 electron transfer at two different sites: {a) within the PS 2 reaction centre by impairment of primary charge separation (P680 Pheo Qa P680+Pheo'QA), and (7>) on tiie PS 2 donor side by inhibition of the electron transfer from to P680+. (2) In PS 2 membrane fragments with intact 02-evolution the primary charge separation is the most sensitive target of the photoinhibition by "visible light". The UV-B irradiation, however, affects predominantly the oxygen-evolving complex or the electron transfer from the oxygen-evolving complex to Yz®’'. (5) Susceptibility of the P680 Yz segment to photoinhibition by "visible light" is drastically increased in the samples with lifetimes of Yz°* and P680+ having been signifícantly prolonged by Tris- treatment. Susceptibility of the primaiy charge separation to photoinhibition, however, is not dependent on the lifetimes of P680+ and Yz®’'.

Language:

Multiple languages

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Coverage:

355-368 and 91-104

Source:

Photosynthetica | 1992 Volume:27 | Number:3

Harvested from:

CDK

Metadata only:

false