cDNA cloning of a novel lectin-like xylem sap protein and its root-specific expression in cucumber

Abstract

A novel cDNA encoding a major 30-kDa protein in xylem sap of cucumber Cucumis sativus (XSP30) was homologous to the B chains of galactose-binding lectins such as ricin and abrin. XSP30 gene was specifically expressed in roots, and XSP30 was immunologically detected only in the xylem sap, but not in any organs.