Nucleotide Sequence of a cDNA Encoding a Pathogenesis-Related Protein, P1-p14, from Tomato (Lycopersicon esculentum)

Abstract

We report the sequence of a cDNA clone, pTE 28.1, corresponding to a tomato (Lycopersicon esculentum) pathogenesis-related protein mRNA. It was selected from an ethylene-treated tomato leaf cDNA XZAP I1 library screened by differential hybridization with single-stranded cDNA probes prepared from untreated and ethylene-treated leaf poly(A') RNA. The pTE 28.1 cDNA clone is 711 bp long. The open reading frame encodes a precursor protein of 159 amino acids, and the molecular m a s of the deduced protein is similar to that predicted by in vitro translation-immunoprecipitation experiments (Vera et al., 1989). The first 24 amino acids represent a signal peptide that is processed to render the mature protein as previously described (Vera et al., 1989). The deduced protein sequence from the pTE 28.1 cDNA contains five additional amino acid residues (Trp-ArgAsn-Ser-Val) positioned between amino acid 97 and 98 of the published sequence of p14 obtained by direct protein sequencing (Lucas et al., 1985). Three potential polyadenylation signals, AAAATA, AAATA, and TAATATGAATAA are found in the 3' noncoding region. A search for homologies in data banks revealed coincidence with a cDNA clone (P6) isolated from fungi-infected tomato leaves (EMBL:M69248, J.A. Van Kan, unpublished data), but the pTE 28.1 clone we have obtained extends 25 more nucleotides in the 5' end. pTE 28.1 clone also shows similarities with counterpart pathogenesis-related genes from tobacco (Cornelissen et al., 1986).