Steroidal saponins are not main building units of the prolamellar body in etioplasts

Sugar-containing lipids were analyzed by thin layer chromatography in various cell fractions of etiolated Aoena leaves, Auena intact etioplasts and prolamellar bodies isolated from Cucurbita etioplasts. We confirmed the presence of steroidal saponins, avenacosides A and B in etiolated leaves and crude etioplast fraction of Avena, but scarcely detected them in Avena intact etioplasts purified by Percoll density gradient centrifugation. Saponins were hardly detected in the paracrystalline prolamellar bodies from Cucurbita etioplasts. We concluded that steroidal saponins are not main building units of the prolamellar body in the etioplasts.