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Chloroplast Biogenesis 81: Transient Formation of Divinyl Chlorophyll a Following a 2.5 ms Light Flash Treatment of Etiolated Cucumber Cotyledons
Author(s) -
Adra Al Numan,
Rebeiz Constantin A.
Publication year - 1998
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1998.tb05295.x
Subject(s) - etiolation , chloroplast , biogenesis , flash (photography) , transient (computer programming) , botany , chlorophyll , biology , chemistry , physics , optics , computer science , biochemistry , enzyme , operating system , gene
— The possible conversion of nascent divinyl (DV) chloro‐phyllide a (Chlide a ) to DV chlorophyll a (Chi a during the early stages of greening in a dark divinyl‐light divinyl‐light/dark divinyl (DDV‐LDV‐LDDV) plant species was investigated. Etiolated cucumber cotyledons ( Cucu‐mis sativus L .) were subjected to a 2.5 ms light flash followed by darkness. The DV and monovinyl (MV) components of the protochlorophyllide a (Pchlide a ), Chlide a , Pchlide a ester and Chi a pools were monitored quantitatively by high‐resolution spectrofluorometry, immediately following the light treatments and after various periods in darkness. The light treatment photoconverted DV and MV Pchlide a to DV and MV Chlide a . Some photoconversion of MV Pchlide a ester to MV Chi a also appeared to take place. A sharp rise in the level of DV Chi a following the light treatment could not be accounted for by photoconversion of DV Pchlide a ester. It must have arisen by rapid esterification of nascent DV Chlide a. After illumination, the level of DV Chi a rose for 5 s and then declined. The implications of the transient rise and fall of DV Chi a content following illumination to the Chi a biosynthetic heterogeneity is discussed.