Genes encoding oleosins in maize kernel of inbreds Mo17 and B73

Abstract

We have investigated all three oleosin genes which are expressed in the kernel of maize (Zea mays L., Mo17). Oleosin genes, ole16, ole17, and ole18, encode OLE16, OLE17, and OLE18, respectively, in proportional amounts of approximately 2:1:1 in isolated oil bodies. None of the three genes has an intron or a sequence encoding an N-terminal signal peptide. The three genes are expressed coordinately during seed maturation, and their encoded oleosins are present in similar proportional amounts in oil bodies isolated from the embryonic axis, scutellum, and aleurone layer. OLE16 represents one oleosin isoform, whereas OLE17 and OLE18 are close members of another oleosin isoform. ole16 and ole18 have been mapped to single loci on chromosomes 2 (near b1 gene) and 5S (near phya2), respectively. We predict that ole17 is located on chromosome 1 (near phya1), in a chromosomal segment duplicated on chromosome 5.