TY - JOUR
T1 - Dichromate effect on energy dissipation of photosystem II and photosystem I in Chlamydomonas reinhardtii
AU - Perreault, François
AU - Ait Ali, Nadia
AU - Saison, Cyril
AU - Popovic, Radovan
AU - Juneau, Philippe
N1 - Funding Information:
The authors thank Dr. Laszlo Kovacs for his critical reading and suggestions during preparation of this manuscript. This research was supported by the Natural Science and Engineering Council of Canada (NSERC) through Grants GP0093404 awarded to R. Popovic and 262210 awarded to P. Juneau.
PY - 2009/7/17
Y1 - 2009/7/17
N2 - In this study, we investigated the energy dissipation processes via photosystem II and photosystem I activity in green alga Chlamydomonas reinhardtii exposed to dichromate inhibitory effect. Quantum yield of photosystem II and also photosystem I were highly decreased by dichromate effect. Such inhibition by dichromate induced strong quenching effect on rapid OJIP fluorescence transients, indicating deterioration of photosystem II electron transport via plastoquinone pool toward photosystem I. The decrease of energy dissipation dependant on electron transport of photosystem II and photosystem I by dichromate effect was associated with strong increase of non-photochemical energy dissipation processes. By showing strong effect of dichromate on acceptor side of photosystem I, we indicated that dichromate inhibitory effect was not associated only with PSII electron transport. Here, we found that energy dissipation via photosystem I was limited by its electron acceptor side. By the analysis of P700 oxido-reduction state with methylviolagen as an exogenous PSI electron transport mediator, we showed that PSI electron transport discrepancy induced by dichromate effect was also caused by inhibitory effect located beyond photosystem I. Therefore, these results demonstrated that dichromate has different sites of inhibition which are associated with photosystem II, photosystem I and electron transport sink beyond photosystems. Crown
AB - In this study, we investigated the energy dissipation processes via photosystem II and photosystem I activity in green alga Chlamydomonas reinhardtii exposed to dichromate inhibitory effect. Quantum yield of photosystem II and also photosystem I were highly decreased by dichromate effect. Such inhibition by dichromate induced strong quenching effect on rapid OJIP fluorescence transients, indicating deterioration of photosystem II electron transport via plastoquinone pool toward photosystem I. The decrease of energy dissipation dependant on electron transport of photosystem II and photosystem I by dichromate effect was associated with strong increase of non-photochemical energy dissipation processes. By showing strong effect of dichromate on acceptor side of photosystem I, we indicated that dichromate inhibitory effect was not associated only with PSII electron transport. Here, we found that energy dissipation via photosystem I was limited by its electron acceptor side. By the analysis of P700 oxido-reduction state with methylviolagen as an exogenous PSI electron transport mediator, we showed that PSI electron transport discrepancy induced by dichromate effect was also caused by inhibitory effect located beyond photosystem I. Therefore, these results demonstrated that dichromate has different sites of inhibition which are associated with photosystem II, photosystem I and electron transport sink beyond photosystems. Crown
KW - Chlamydomonas reinhardtii
KW - Dichromate toxicity
KW - Energy dissipation processes
KW - Photosynthesis
KW - Photosystem I
KW - Photosystem II
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U2 - 10.1016/j.jphotobiol.2009.03.011
DO - 10.1016/j.jphotobiol.2009.03.011
M3 - Article
C2 - 19427227
AN - SCOPUS:67349248428
SN - 1011-1344
VL - 96
SP - 24
EP - 29
JO - Journal of Photochemistry and Photobiology B: Biology
JF - Journal of Photochemistry and Photobiology B: Biology
IS - 1
ER -