A cDNA clone (TAB7) encoding a putative wound-induced (Win) protein has been isolated from a tomato (Lycopersicon esculentum Mill. cv. Ailsa Craig) leaf abscission zone cDNA library using a differential screening strategy. The clone has a high degree of homology at the amino acid level to both the potato win1 and 2 genes, Hevea brasiliensis hevein and Nicotiana tabacum PR-4a and PR-4b proteins. The mRNA encoded by TAB7 is up-regulated within 12 h of exposure to ethylene (10 μl l^-1) and its expression increases steadily within the cells comprising the leaf abscission zone and to a lesser extent in the adjacent non-zone tissue. This rise precedes the onset of cell separation. Southern analysis indicates that the mRNA is encoded by either a single gene or a small gene family. The role of the protein during abscission is discussed.