OPAQUE-15, A MAIZE MUTATION WITH PROPERTIES OF A DEFECTIVE OPAQUE-2 MODIFIER

An opaque mutation was identified that reduces gamma-zein synthesis in maize endosperm. The mutation, opaque-15, causes a 2- to 3-fold reduc tion in gamma-zein mRNA and protein synthesis and reduces the proporti on of the 27-kDa gamma-zein A gene transcript. Although the protein bo dies in opaque-15 are similar in size and morphology compared to wild type, there are fewer of them in developing endosperm cells. The opaqu e-15 mutation maps near the telomere of chromosome 7L, coincident with an opaque-2 modifier locus. Based on its phenotype, opaque-15 appears to be a mutation of an opaque-2 modifier gene.