Plant Physiology Unit, Commonwealth Scientific and Industrial Research Organization, Division of Food Research, and School of Biological Sciences, Macquarie University, North Ryde 2113, Sydney, Australia.
Plant Physiol. 1972 Apr;49(4):467-70. doi: 10.1104/pp.49.4.467.
The photo-oxidation of cytochrome f (cytochrome c(554)) in bundle sheath cells isolated from leaves of maize (Zea mays var. DS 606A) has been compared with that in intact maize leaf and in isolated pea leaf cells (Pisum sativum L.). In all cases, illumination with red light caused a negative absorbance change at 554 nm which was attributed to the oxidation of cytochrome f. The extent of this change was greater using monochromatic red light at wavelengths above 700 nm compared with wavelengths below 700 nm. 3-(3,4-Dichlorophenyl)-1, 1-dimethylurea abolished this difference in bundle sheath cells. After illumination for 1 minute or longer in bundle sheath cells, reduction of cytochrome f in the dark was rapid only if the wavelength of the illuminating light was below 700 nm. In the presence of 3-(3,4-dichlorophenyl)-1, 1-dimethlyurea, reduction was slow after illumination at all wavelengths.Cytochrome f photo-oxidation was also followed in cells of a mutant of Chlamydomonas reinhardi, ac-21, which has isolated chloroplasts that exhibit photochemical reactions similar to those shown by isolated bundle sheath chloroplasts. No evidence was obtained for photoreduction of cytochrome f in the mutant.It was concluded that in the chloroplast of the intact bundle sheath cell of maize there is electron flow between photosystem II and cytochrome f resulting in photoreduction of the cytochrome.
玉米（Zea mays var. DS 606A）叶片分离的束鞘细胞中细胞色素 f（细胞色素 c(554)）的光氧化作用与完整玉米叶片和分离的豌豆叶片细胞（Pisum sativum L.）中的光氧化作用进行了比较。在所有情况下，用红光照射都会导致 554nm 处的负吸光度变化，这归因于细胞色素 f 的氧化。与波长低于 700nm 的光相比，使用波长高于 700nm 的单色红光时，这种变化更为明显。3-(3,4-二氯苯基)-1,1-二甲基脲（3-(3,4-Dichlorophenyl)-1,1-dimethylurea）消除了束鞘细胞中这种差异。在束鞘细胞中照射 1 分钟或更长时间后，如果照射光的波长低于 700nm，则黑暗中细胞色素 f 的还原速度很快。在 3-(3,4-二氯苯基)-1,1-二甲基脲存在的情况下，在所有波长下照射后还原速度都很慢。在 Chlamydomonas reinhardi ac-21 的突变体细胞中也跟踪了细胞色素 f 的光氧化作用，该突变体具有分离的叶绿体，其光化学反应与分离的束鞘叶绿体相似。在突变体中没有获得细胞色素 f 光还原的证据。因此得出结论，在完整的玉米束鞘细胞的叶绿体中，存在电子从光系统 II 到细胞色素 f 的流动，从而导致细胞色素 f 的光还原。
