Acrolein, an α,β-unsaturated carbonyl, inhibits both growth and PSII activity in the cyanobacterium Synechocystis sp. PCC 6803.
In this study, we sought to determine whether and how an α,β-unsaturated carbonyl, acrolein, can inhibit the growth of the cyanobacterium Synechocystis sp. PCC6803 (S. 6803). Treatment of S. 6803 with 200 µM acrolein for 3 d significantly and irreversibly inhibited its growth. To elucidate the inhibitory mechanism, we examined the effects of acrolein on photosynthesis. In contrast to dark conditions, the addition of acrolein to S. 6803 under conditions of illumination lowered the CO₂-dependent O₂ evolution rate (photosynthetic activity). Furthermore, treatment with acrolein lowered the activity reducing dimethyl benzoquinone in photosystem II (PSII). Acrolein also suppressed the reduction rate for the oxidized form of the reaction center chlorophyll of photosystem I (PSI), P700. These results indicate that acrolein inhibited PSII activity in thylakoid membranes. The addition of 200 µM acrolein to the illuminated S. 6803 cells gradually increased the steady-state level (Fs) of Chl fluorescence and decreased the quantum yield of PSII. These results suggested that acrolein damaged the acceptor side of PSII. On the other hand, acrolein did not inhibit respiration. From the above results, we gained insight into the metabolism of acrolein and its physiological effects in S. 6803.
Department of Biological and Environmental Sciences, Faculty of Agriculture, Graduate School of Agricultural Science, Kobe University.
Ginga
G
Shimakawa
Tatsuya
T
Iwamoto
Tomohito
T
Mabuchi
Ryota
R
Saito
Hiroshi
H
Yamamoto
Katsumi
K
Amako
Toshio
T
Sugimoto
Amane
A
Makino
Chikahiro
C
Miyake
D000171:Acrolein / Q000494:pharmacology*; D016227:Benzoquinones / Q000737:chemistry / Q000378:metabolism; D002245:Carbon Dioxide / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D010788:Photosynthesis / Q000187:drug effects*; D045332:Photosystem II Protein Complex / Q000187:drug effects; D046939:Synechocystis / Q000187:drug effects* / Q000254:growth & development
D016227:Benzoquinones; D045332:Photosystem II Protein Complex; D002245:Carbon Dioxide; C004532:quinone; D000171:Acrolein; D010100:Oxygen