ISSN:
1432-2048
Keywords:
Avena
;
Chlorophyll biosynthesis
;
Etioplasts
;
Geranylgeranyldiphosphate
;
Protoplasts
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The uptake of [1-3H]geranylgeranyl diphosphate (GGPP) into protoplasts and intact etioplasts and the metabolic interconversion therein was studied after a 2 min pulse of white light. The chlorophyll synthetase reaction, Chlide+GGPP→ChlGG, was taken as a natural probe for the etioplast compartment. This reaction yields labeled ChLGG and, by hydrogenation, labeled ChlP, when [1-3H]GGPP receives access to the etioplast stroma. It was found that penetration across the plastid envelope was rapid and that penetration across the plasma membrane of protoplasts, however, was slow. A cellular pool of soluble GGPP was detected. This pool was lost, in part, during preparation of the protoplasts and almost completely during preparation of the etioplasts. The membrane-bound phytol pool of etioplasts could not be replaced by exogenous [3H]GG. The endogenous GG and phytol pools of protoplasts, which were larger than those of etioplasts, could be replaced in part by exogenous [3H]GGPP. That part of this pool exists as soluble GGPP or as a direct precursor in the cytoplasm is discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00384985
