Isolation of the genomic clone for pathogenesis-related protein 1a from Nicotiana tabacum cv. Xanthi-nc

We describe the isolation of the chromosomal gene for pathogenesis-related protein 1a from Nicotiana tabacum. A 2 kb fragment containing the PR-1a gene as well as 5' and 3' flanking DNA has been sequenced and the transcriptional start site has been determined by primer extension and S1 nuclease mapping. 80% of the protein sequence from purified PR-1a and 20% of the sequence of purified PR-1b has also been determined and used to verify the nomenclature established for the PR-1 cDNAs.