Isolation and characterization of polyribosomes and non-ribosomal ribonucleoprotein particles from the duckweed Spirodela oligorrhiza

Abstract Polyribosomes and non-ribosomal ribonucleoprotein (RNP) particles were isolated from the duckweed Spirodella oligorrhiza . Cytoplasmic polyribosomes from light-grown plants are generally larger than cytoplasmic polyribosomes from dark-grown plants. Non-ribosomal RNP particles from both light-grown and dark-grown plants sediment at about 25 S and have a buoyant density in CsCl of 1.39 g/cm 3 . They show a relative stability in high-salt solutions, do not contain rRNA and show large differences in protein content and composition as compared with ribosomes.