Expression of genes encoding the rice translation initiation factor, eIF5A, is involved in developmental and environmental responses.
Eukaryotic translation initiation factor 5 A (eIF5A) is the only cellular protein known to contain the unusual amino acid hypusine. However, the precise cellular function of eIF5A is to date unknown. In the present study, we report on the characterization of two cDNA clones encoding eIF5A in rice (Oryza sativa). Sequence analysis revealed that the two cDNAs share 93% amino acid sequence identity. Phylogenetic analysis of the eIF5A genes revealed paraphyly of OseIF5A-1 and OseIF5A-2. Analysis at the mRNA level has shown that OseIF5A-1 and OseIF5A-2 are expressed in rice leaves and panicles and high relative amounts of both genes were detected in old leaves. In addition, both OseIF5A-1 and OseIF5A-2 were spatially regulated during rice leaf development. In suspension-cultured cells, the transcripts of OseIF5A genes were strongly reduced after sugar starvation. Abiotic stresses, salt and heavy metal, induce the accumulation of OseIF5A-1 and OseIF5A-2 mRNAs in rice cells. These results suggested that both OseIF5A genes might be regulated by plant development and environmental stresses.
Chou
Wan-Chi
WC
Department of Biology, Center for Biosciences and Biotechology, National Cheng Kung University, Tainan 701, Taiwan.
Huang
Ya-Wen
YW
Tsay
Wen-Su
WS
Chiang
Tzen-Yuh
TY
Huang
Dinq-Ding
DD
Huang
Hao-Jen
HJ