The submergence-induced gene OsCTP in rice (Oryza sativa L.) is similar to Escherichia coli cation transport protein ChaC

We used suppression subtractive hybridization (SSH) to identify submergence-induced genes from the submergence-tolerant rice cultivar, FR13A. These genes putatively encode four proteins including a cation transport protein (OsCTP), monogalactosyl-diacylglycerol synthase, a cold-induced protein and glutathione synthetase. The full-length gene of one upregulated clone, OsCTP was generated by rapid amplification of cDNA ends. The gene comprises 741 bp with an open reading frame of 414 bp (nt 51-464) that encodes a putative protein of 137 amino acids. The theoretical isoelectric point of the putative protein is 5.35 and the molecular weight is 15.2 kDa. Six exons and five introns of the OsCTP gene correspond to 3582-2296 bp of accession number AAAA01013244 from the rice genome. OsCTP expression is enhanced by submergence as well as stress induced by abscisic acid, salt or drought. OsCTP might encode a novel cation transport protein similar to Escherichia coli ChaC and may be associated with a general defensive response to various environmental stresses.