STRUCTURAL ORGANIZATION OF STR 246C AND STR 246N, PLANT DEFENSE-RELATED GENES FROM NICOTIANA-TABACUM

We have previously identified a cDNA clone, pNt246, whose correspondin g transcripts accumulate in leaves in response to inoculation by compa tible and incompatible isolates of the phytopathogenic bacterium Pseud omonas solanacearum [19]. We now describe the nucleotide sequence of a genomic clone, str 246C, corresponding to this cDNA species, and of a related genomic clone, sfr 246N, which appears to be a pseudogene wit h a 5'-end deletion. The nucleotide sequence of the str 246C gene was found to be identical to that of the parA gene, previously shown to be regulated by auxin [28, 29]. Upstream of the str 246N gene, sequences homologous to a Barn HI repetitive element described in Vicia faba [1 5] are present within an ORF showing significant homologies to an inte grase-encoding gene of several retroviruses. This observation indicate s that this highly repetitive DNA originates from sequences present in transposable mobile elements.