TY - JOUR
T1 - Photooxidation of cytochrome b-559 in leaves and chloroplasts at room temperature
AU - Hiller, R. G.
AU - Anderson, Jan M.
AU - Boardman, N. K.
PY - 1971/9/7
Y1 - 1971/9/7
N2 - 1. Light-induced absorbance changes of cytochrome b-559 and cytochrome f in the α-band region were examined in leaves and in isolated chloroplasts. 2. Absorbance changes of cytochrome b-559 were not detected in untreated leaves or in most preparations of isolated chloroplasts. After treatment of leaves or chloroplasts with carbonyl cyanide m-chlorophenylhydrazone, high rates of photooxidation of cytochrome b-559 were obtained, both in far-red (>700 nm) and red actinic light. Cytochrome f was photooxidized in far-red light, but in red light it remained mainly in the reduced state. The initial rates of photooxidation of cytochrome b-559 in leaves or chloroplasts treated with carbonyl cyanide m-chlorophenylhydrazone were considerably decreased by 3-(3′,4′-dichlorophenyl)-1,1-dimethyl urea. 3. A slow photoreduction of cytochrome b-559 was observed in aged mutant pea chloroplasts in red light. 4. The results do not support the view that cytochrome b-559 is a component of the electron transport chain between the light reactions. It is suggested that cytochrome b-559 is located on a side path from Photosystem II, but with a possible additional link to Photosystem I.
AB - 1. Light-induced absorbance changes of cytochrome b-559 and cytochrome f in the α-band region were examined in leaves and in isolated chloroplasts. 2. Absorbance changes of cytochrome b-559 were not detected in untreated leaves or in most preparations of isolated chloroplasts. After treatment of leaves or chloroplasts with carbonyl cyanide m-chlorophenylhydrazone, high rates of photooxidation of cytochrome b-559 were obtained, both in far-red (>700 nm) and red actinic light. Cytochrome f was photooxidized in far-red light, but in red light it remained mainly in the reduced state. The initial rates of photooxidation of cytochrome b-559 in leaves or chloroplasts treated with carbonyl cyanide m-chlorophenylhydrazone were considerably decreased by 3-(3′,4′-dichlorophenyl)-1,1-dimethyl urea. 3. A slow photoreduction of cytochrome b-559 was observed in aged mutant pea chloroplasts in red light. 4. The results do not support the view that cytochrome b-559 is a component of the electron transport chain between the light reactions. It is suggested that cytochrome b-559 is located on a side path from Photosystem II, but with a possible additional link to Photosystem I.
UR - http://www.scopus.com/inward/record.url?scp=0015214201&partnerID=8YFLogxK
U2 - 10.1016/0005-2728(71)90161-7
DO - 10.1016/0005-2728(71)90161-7
M3 - Article
C2 - 5160746
AN - SCOPUS:0015214201
VL - 245
SP - 439
EP - 452
JO - Biochimica et Biophysica Acta - Bioenergetics
JF - Biochimica et Biophysica Acta - Bioenergetics
SN - 0005-2728
IS - 2
ER -