ISSN:
1432-072X
Keywords:
Blue-green algae
;
Photosystem II
;
Diphenylcarbazide
;
3-(3,4-Dichlorophenyl)-N-N′-dimethyl urea
;
Sensitivity
;
Oscillatoria chalybea
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Thylakoids of Oscillatoria chalybea are able to split water. The Hill reaction of these thylakoids is sensitive to DCMU. Diphenylcarbazide can substitute for water as the electron donor to photosystem II with these fully functioning thylakoids. However, the diphenylcarbazide photooxidation is completely insensitive to 3-(3,4-dichlorophenyl)-N-N′-dimethyl urea (DCMU) at high diphenylcarbazide concentrations. In with Tris-treated Oscillatoria thylakoids the water splitting capacity is lost and diphenylcarbazide restores electron transport through photosystem II as occurs with higher plant chloroplasts. However, also these photoreactions are insensitive to DCMU. If diphenylcarbazide acts in Oscillatoria as an electron donor to photosystem II the result suggests that diphenylcarbazide feeds in its electrons behind the DCMU inhibition site. This in turn indicates that in Oscillatoria the site of inhibition of DCMU is on the donor side of photosystem II.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00446451
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