HETEROGENEITY OF THE PHOTOCHEMICAL CENTERS IN SYSTEM II OF CHLOROPLASTS*

Photochemistry and Photobiology - Tập 23 Số 5 - Trang 343-350 - 1976
Anastasios Melis1, Peter H. Homann1
1Department of Biological Science, Florida State University, Tallahassee, FL 32306, U.S.A.

Tóm tắt

Abstract— In 3‐(3,4‐dichlorophenyl)‐1,1‐dimethylurea (DCMU) poisoned chloroplasts of algae and‘ higher plants the area over the fluorescence induction curve increases with biphasic first order kinetics (Melis and Homann, 1975). Two possibilities are considered to explain the biphasic nature of the area growth. The first is a sequential double reduction of the primary electron acceptor in system II while the second envisages a heterogeneity of its photochemical centers. The kinetic properties of the area growth after firing a single saturating flash proved to be incompatible with the predictions of the “sequential double reduction” model. This conclusion was corroborated by results obtained from a kinetic analysis of the area restoration process in the dark, and an analysis of the partially restored areas.Assuming an existence of a heterogeneous pool of photochemical centers, the growth of the area over the fluorescence curve could be further analyzed to yield two components, a fast a‐component, and a relatively slow β‐component. The kinetic characteristics of these components, and the effect of a short saturating flash on their respective size, led to the conclusion that one type of photochemical center had a faster recombination rate of the photochemically separated charges and was less efficient in trapping excitation energy.

Từ khóa


Tài liệu tham khảo

10.1016/0005-2728(70)90227-6

10.1016/0005-2728(73)90260-0

Briantais J. M., 1972, Photosynthetica, 6, 133

10.1016/0005-2728(73)90212-0

10.1016/0005-2728(73)90258-2

10.1016/0022-5193(67)90112-9

10.1016/S0006-3495(72)86126-5

Duysens L. N. M., 1963, Studies on Microalgae and Photosynthetic Bacteria, 353

10.1016/0005-2728(74)90134-0

10.1016/0014-5793(74)80284-X

10.1016/B978-0-12-282606-1.50007-6

10.1016/S0006-3495(70)86363-9

10.1007/BF00390153

10.1016/0005-2728(68)90062-5

10.1016/0005-2728(71)90015-6

10.1104/pp.41.3.533

Joliot A., 1964, C.R. Acad. Sci. (Paris), 258, 4622

Joliot P., 1971, Proc. 2nd Internal. Cong, on Photosynthesis Research, Stresa, 26

10.1016/0005-2728(73)90178-3

10.1016/0005-2728(73)90179-5

10.1016/0005-2728(70)90138-6

Lavorel J., 1972, C.R. Acad. Sci. (Paris), 274, 2909

10.1016/S0006-3495(72)86125-3

10.1016/0926-6585(66)90001-X

10.1111/j.1751-1097.1975.tb06701.x

10.1051/jcp/1964610674

10.1016/0005-2728(74)90150-9

10.1016/0926-6585(66)90273-1

10.1016/0005-2728(73)90207-7

Tumerman L. A., 1967, Mol. Biol., 1, 628

10.1016/0005-2728(73)90159-X

Thông tin
Thông tin xuất bản

Photochemistry and Photobiology

Tập 23 Số 5

343-350

Thông tin tác giả