Open AccessProtein Synthesis in Imbibing Wheat Embryos
Author(s) -
CUMING Andrew C.,
LANE Byron G.
Publication year - 1979
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1979.tb13248.x
Subject(s) - imbibition , rna , embryo , lysis , biochemistry , reticulocyte , protein biosynthesis , ribosomal rna , heterologous , biology , homologous chromosome , gel electrophoresis , chemistry , microbiology and biotechnology , botany , germination , gene
Polypeptides synthesized by imbibing wheat embryos have been compared with those made by cell‐free extracts programmed with bulk poly(A)‐rich RNA from dry wheat embryos. Newly synthesized polypeptides, labeled with [ 35 S]methionine, were resolved by one‐dimensional and two‐dimensional electrophoresis and then records of the separations were prepared by fluorography. When programmed by bulk poly(A)‐rich RNA from dry wheat embryos, a nuclease‐treated rabbit reticulocyte lysate synthesizes an array of polypeptides which is broadly similar to that formed when a wheat germ extract is programmed with the same RNA. Polypeptides made in both homologous and heterologous cell‐free systems, under the direction of bulk poly(A)‐rich RNA from dry wheat embryos, are broadly similar to those formed during early (0–40 min) imbibition of dry wheat embryos. As imbibition progresses beyond 40 min, there are profound changes in the one‐dimensional and two‐dimensional electrophoretic distributions of newly made polypeptides present in the 23000 × g supernatant fraction of cell‐free homogenates; characteristically, low‐molecular‐weight and basic polypeptides comprise a diminishing proportion of the total polypeptides as imbibition progresses beyond 40 min. Ribosomal proteins are conspicuous among the proteins formed during early imbibition and especially prominent among the products formed when homologous cell‐free polypeptide synthesis is programmed by bulk poly(A)‐rich RNA from dry wheat embryos.