Genomic structure of the gene for copper/zinc‐superoxide dismutase in rice

Abstract

We have isolated and determined the nucleotide sequence of the structural gene (sodB) coding for one of the copper/zinc-superoxide dismutase (Cu/Zn-SOD) isozymes from rice plants (Oryza sativa L.). The sodB gene is split into 8 exons spread about 2 kb of the chromosomal DNA, with the coding sequence beginning in the 2nd and ending in the 8th. Although none of sodB introns are inserted into similar positions in Cu/Zn-SOD genes from other sources, four of six introns in the protein-coding region are located at discriminating positions within structural domains of the protein. Genomic Southern analysis indicated that cytosolic Cu/Zn-SOD is coded for by 2-3 genes in the rice genome.