Isolation, characterization and mRNA expression of four cDNAs encoding translation elongation factor 1A from rice (Oryza sativa L.)

Four different cDNA clones encoding protein synthesis elongation factor 1A, eEF1A, were isolated from rice (Oryza sativa L.). The genes encoded by these cDNAs were designated rice elongation factor 1A genes refa1, refa2, refa3 and refa4. The genes encoded identical eEF-1A polypeptides and shared high amino acid identity with eEF1A of other eukaryotes. Southern blot analysis suggested that some of these I-efa genes may be organized in a cluster on the same chromosome within a short distance. PCR analysis of rice genomic DNA showed that refa1 and refa4, and refa3 and refa2 are in neighboring locations on the rice genome. The mRNAs of the four refa genes accumulated to nearly equal levels in a variety of tissues and at different stages of growth. Suspension-cultured cells were the most abundant in refa mRNAs. Dormant seeds contained a small amount of the four refa mRNAs. Transcript accumulation was highly induced after seed germination, and the same expression levels were maintained even in old leaf blades of mature plants.