WHEAT EMBRYO RIBONUCLEATES .14. MASS ISOLATION OF MESSENGER-RNA FROM WHEAT-GERM AND COMPARISON OF ITS TRANSLATIONAL CAPACITY WITH THAT OF MESSENGER-RNA FROM IMBIBING WHEAT EMBRYOS

Commercially milled wheat germ is a convenient source material for facile recovery of mass (milligram) quantities of highly purified poly(A)-rich RNA. This poly(A)-rich RNA is efficiently translated in a nuclease-treated extract of rabbit reticulocytes. By sucrose density gradient fractionation of bulk poly(A)-rich RNA from wheat germ, it has been possible to show that there is a direct relationship between the MW of the polypeptide products of cell-free synthesis and the molecular weights of the wheat mRNA molecules which program their synthesis. As assessed by SDS[sodium dodecyl sulfate]-polyacrylamide gel electrophoresis, the same array of polypeptides is synthesized when nuclease-treated reticulocyte extract is programmed by poly(A)-rich RNA from either commercially supplied or laboratory-prepared wheat embryos. Significantly, there are gross quantitative if not qualitative differences between the translational capacities of poly(A)-rich RNA from dry and imbibing wheat embryos, and the possible importance of these differences for interpreting a changing pattern of polypeptide synthesis in imbibing wheat embryos is the subject of a brief discussion.