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Characterization of the quenching of chlorophyll a fluorescence by beta-carotene using the non-linear analysis

Domenii publicaţii > Biologie + Tipuri publicaţii > Articol în revistã ştiinţificã

Autori: Gazdaru D. M. and Iorga B.

Editorial: Photosynthetica, 39(4), p.607-609, 2001.


Carotenoids (Car) regulate energy flow in photosynthesis by a specific Car-chlorophyll (Chl) interaction in the singlet-excited states, leading to a reduction in Chl fluorescence. We studied quenching of Chl a-fluorescence in benzene by trans–carotene. Non-linear analysis of the quenching process enables to explain the possible molecular mechanism leading to the de-excitation of Chl a. The fluorescence intensity was measured at 670 nm for excitation wavelengths of 380, 430, 640, and 650 nm. The -carotene concentrations ranged from 4×10^-5 M to 5×10^-3 M. When the samples were excited at 640 and 650 nm, the Stern-Volmer plots showed that the quenching process has high rate constants, hence -carotene is a very efficient quencher. Two different types of quenching process could take place.
[ISI impact factor in 2001: 0.807]

Cuvinte cheie: fluorescence quenching, photosynthesis // fluorescence quenching, photosynthesis