ISSN:
1573-5079
Keywords:
etiolated leaves
;
non-fluorescent intermediate
;
protochlorophyllide photoreduction
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract By methods of difference and derivative spectroscopy it was shown that in etiolated leaves at 77 K three photoreactions of P650 protochlorophyllide take place which differ in their rates and positions of spectral maxima of the intermediates formed in the process: P650→R668, P650→R688, and P650→R697. With an increase of temperature up to 233 K, in the dark, R688 and R697 are transformed into the known chlorophyllide forms C695/684 and C684/676, while R668 disappears with formation of a shorter wavelength form of protochlorophyllide with an absorption maximum at 643–644 nm. Along with these reactions, at 77 K phototransformations of the long-wave protochlorophyllide forms with absorption maxima at 658–711 nm into the main short-wave forms of protochlorophyllide are observed. At 233 K in the dark this reaction is partially reversible. This process may be interpreted as a reversible photodisaggregation of the pigment in vivo. The mechanism of P650 reactions and their role in the process of chlorophyll photobiosynthesis are discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00146410
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