In vivo assay of P700 redox changes in the cyanobacterium Fremyella diplosiphon and the role of cytochrome c oxidase in regulation of photosynthetic electron transfer

Title:

In vivo assay of P700 redox changes in the cyanobacterium Fremyella diplosiphon and the role of cytochrome c oxidase in regulation of photosynthetic electron transfer

Creator:

Schubert, H., Matthijs, H.C.P., and Mur, L.R.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:3169012c-1b34-47a1-bef2-d5b69173ecf2
uuid:3169012c-1b34-47a1-bef2-d5b69173ecf2
urnnbn:urn:nbn:cz:aba007-000fp6

Subject:

Chlorella pyrenoidosa, pulse amplitude modulation (PAM), photosystem 2, photosystem 1, Passiflora sp., KCN, far-red radiation, and chlorophyli fluorescence

Type:

model:internalpart and TEXT

Format:

print

Description:

Photosynthetic and respirátory electron transfers in cyanobacteria not only serve the bioenergetic needs of these prokaryotes during day and night time. The common use of the plastoquinone pool and the cytochrome (cyt) complex also establishes possibilities for sharing photosystem (PS) 2 plus dehydrogenases at the donor side and cyt c oxidase plus PSI at the acceptor side. Given metabolic conditions and radiant energy supply, the available choices may give rise to unusual combinations of connected electron transfer activities, for example PS2 and cyt c oxidase. In vivo measurements of energy storage in PSI cyclic photophosphorylation via photoacoustic spectroscopy, and of the P700 redox statě via absorbance changes at 820 nm detected with the pulse amplitudě modulation technique (PAM), as well as of PS2 fluorescence yield, all in the absence or presence of the cyt c oxidase inhibitor KCN were combined to demonstrate that the two pathways at the acceptor side communicate in vivo. This type of regulation serves proper poising of electron flow through and around PSI. The impaired cyt c oxidase activity (in this study achieved by addition of KCN) prevents a truly oxidized statě of P700 to be reached, which hampers electron passage from PS2. The relative overreduction of PS 1 in the KCN intoxicated samples reduces the electron flow directed to biosynthesis. The results illustrate the versatility of the P700 redox statě measurements at 820 nm as a means to study in vivo electron fluxes in cyanobacteria.

Language:

Multiple languages

Rights:

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

Coverage:

517-527 and 39-49

Source:

Photosynthetica | 1995 Volume:31 | Number:4

Harvested from:

CDK

Metadata only:

false