Abstract
We isolated INF1 elicitin-inducible cDNA encoding a pleiotropic drug resistance (PDR)-type ATP-binding cassette (ABC) transporter homolog (NtPDR1) in suspension-cultured tobacco Bright Yellow-2 (BY-2) cells. The NtPDR1 (Nicotiana tabacum PDR protein 1) gene encodes a 162 kDa protein, which includes two putative hydrophilic domains containing ABC signature motif and two putative hydrophobic domains. Expression of the NtPDR1 gene was rapidly and strongly activated by treatment with INF1 elicitin or methyljasmonate in BY-2 cells. The expression of NtPDR1 was similar to expression of NtPAL, a typical defense gene. In addition, treatment of flagellin, which is a bacterial proteinaceous HR elicitor, or treatment of yeast extract, a general elicitor also induced NtPDR1 gene expression. In the promoter sequence of NtPDR1, we found several putative cis-elements including GCC box and jasmonate-responsive elements. These results indicate that NtPDR1 may be one of the basic PR-genes involved in general defense response in tobacco.
