Effects of floury-2 locus on zein accumulation and RNA metabolism during maize endosperm development

Zein accumulation patterns during mutant and normal maize endosperm development were determined. Accompanying an increase in the number of floury-2 alleles present in the endosperm was a well-defined stepwise depression in zein accumulation. Analysis of the zein accumulated in endosperms containing zero, one, two, and three doses of the floury-2 allele by sodium dodecylsulfate--polyacrylamide gel electrophoresis revealed a proportionate reduction in the two major zein components, Z1 and Z2. In contrast, the relative proportions of the minor zein bands were altered. Membrane-bound polysomes isolated from kernels of floury-2 and normal maize were predominantly large size classes. The presence of increasing numbers of the floury-2 allele in the endosperm decreased recovery of membrane-bound polysomal material in a stepwise fashion. However, major alterations in polysome size-class distributions were not observed. The reduction in membrane-bound polysome material correlated linearly with reductions in in vitro zein synthesis and in vivo zein accumulation.