ISSN:
1615-6102
Schlagwort(e):
Chloroplast development
;
Etioplasts
;
Prolamellar body
;
Saponins
;
Galactolipids
;
Sterols
;
Ionic environment
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Biologie
Notizen:
Summary Membranolytic active saponins (26-desglucoavenacosides) derived from isolated oat-avenacosides adsorb to oat prolamellar bodies (PLBs), but not to wheat or rye etioplast inner membranes. Thus, the saponin adsorption is a peculiarity of oat PLBs but not a general tool for PLB-analysis. The qualitative and quantitative analysis of free sterols and galactolipids of isolated PLBs did not explain the exclusive adsorption of saponins to oat PLBs. In addition, isolated PLBs and prothylakoids (PTs) of all three plants did not differ with respect to the molecular species composition of mono- (MGDG) or di-galactosyldiacylglyceride (DGDG). Recrystallization leading to a structural reorganization of wheat PLBs (wide type to narrow type) also had no influence on the molecular species composition of the isolated etioplast inner membranes. These observations as well as earlier investigations raise the question, whether the composition of PLBs is responsible for the tubular, semicrystalline construction. Experiments with the chelating agent EDTA indicate an external influence on the PLB construction and underline the idea that the PLB construction is not influenced by the membrane components themselves. Low concentrations of EDTA in the isolation media decompose the paracrystalline structure of the PLBs into membranes, resembling those of greening plastids. Based on these experiments we assume the ionic environment in plastids to be responsible for the construction and decomposition of PLBs and that changes of the membrane components are of minor importance.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF01354289
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