Deletion analysis from the 3' to the 5' end of the promoter region of the wound-inducible potato proteinase inhibitor IIK gene has identified a 421-base sequence at -136 to -557 that is necessary for expression. Utilizing DNA band-shift assays, a 10-base sequence within the 421-base region was found to bind a nuclear protein from wounded tomato leaves. This 10-base sequence is adjacent to an 8-base consensus sequence at -147 to -155 that is present in the promoter region of several elicitor-inducible genes from various other plants. The evidence suggests that a complex set of cis- and trans-acting elements within the -136 to -165 region of the potato IIK gene may be involved with the signaling mechanisms that regulate the inducibility of this gene in response to pest and pathogen attacks.

The isolation and characterization of a genomic clone encoding proteinase inhibitor II of potato (Solanum tuberosum) is described. The structure of this gene was determined by sequencing a genomic fragment of about 2 kb containing the entire RNA coding as well as about 900 nucleotides of the 5'-upstream and 250 nucleotides of the 3'-downstream region. The transcription start site was determined by RNase protection experiments. The comparison of the genomic sequence with cDNA sequences reveals the presence of one intron with a length of 117 nucleotides. The genomic clone contains an open reading frame of 462 nucleotides allowing for a protein of 154 amino acids. The proteinase inhibitor II gene displays typical features of eucaryotic genes. The sequence TATAAA is found 26 nucleotides upstream of the transcription initiation site and the sequence CAAAT at position--103. In the 3'-region the sequence AATAA is found 33 nucleotides in front of the poly-A addition site.