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Effect of partial or complete elimination of light‐harvesting complexes on the surface electric properties and the functions of cyanobacterial photosynthetic membranes
Author(s) -
Dobrikova Anelia G.,
Domonkos Ildikó,
Sözer Özge,
LaczkóDobos Hajnalka,
Kis Mihály,
Párducz Árpád,
Gombos Zoltán,
Apostolova Emilia L.
Publication year - 2013
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.2012.01648.x
Subject(s) - thylakoid , photosynthesis , biophysics , membrane , photosystem ii , mutant , oxygen evolution , photosynthetic reaction centre , chemistry , photosystem , phycobilisome , biology , cyanobacteria , chloroplast , biochemistry , electrode , electrochemistry , genetics , gene , bacteria
Influence of the modification of the cyanobacterial light‐harvesting complex [i.e. phycobilisomes (PBS)] on the surface electric properties and the functions of photosynthetic membranes was investigated. We used four PBS mutant strains of Synechocystis sp. PCC6803 as follows: PAL (PBS‐less), CK (phycocyanin‐less), BE (PSII‐PBS‐less) and PSI‐less/ apcE − (PSI‐less with detached PBS). Modifications of the PBS content lead to changes in the cell morphology and surface electric properties of the thylakoid membranes as well as in their functions, such as photosynthetic oxygen‐evolving activity, P700 kinetics and energy transfer between the pigment–protein complexes. Data reveal that the complete elimination of PBS in the PAL mutant causes a slight decrease in the electric dipole moments of the thylakoid membranes, whereas significant perturbations of the surface charges were registered in the membranes without assembled PBS–PSII macrocomplex (BE mutant) or PSI complex (PSI‐less mutant). These observations correlate with the detected alterations in the membrane structural organization. Using a polarographic oxygen rate electrode, we showed that the ratio of the fast to the slow oxygen‐evolving PSII centers depends on the partial or complete elimination of light‐harvesting complexes, as the slow operating PSII centers dominate in the PBS‐less mutant and in the mutant with detached PBS.