A comparison of prolamellar bodies from wheat, Scots pine and Jeffrey pine. Pigment spectra and properties of protochlorophyllide oxidoreductase

Inner etioplast membrane fractions were isolated from wheat ( Triticum aestivum L. cv. Starkell), Scots pine ( Pinus sylvestris L.) and Jeffrey pine ( Pinus jeffreyi Murr), in order to investigate whether cotyledons of dark-grown conifers have protochlorophyllide associated to protochlorophyllide oxidoreductase (EC 1.6.99.–) in the pro-lamellar body in the same way as angiosperms. Protochlorophyllide was found to be present in dark-grown seedlings of Scots pine and Jeffrey pine to the same extent as in dark-grown wheat, 10–15.8 nmol (g fresh weight)^?1. Fluorescence emission spectra at 77 K showed accumulation of protochlorophyllide with emission maximum at 657 nm in the prolamellar body fractions of the three species studied. Also the light- and NADPH-dependent activity of protochlorophyllide oxidoreductase was consistently localized in the prolamellar body fractions. The three prolamellar body fractions were dominated by the same polypeptide. Its molecular weight was estimated to be 38 000 by sodium dodecylsulphate polyacrylamide gel electrophoresis.