A six-cysteine type thionin from the radisch storage organ displays weak in vitro antifungal activity against Fusarium culmorum

Abstract

A 5 kDa peptide was purified from the basic protein fraction of radish (Raphanus sativus L.) storage organs. The amino-terminal amino acid sequence of this peptide (43 residues) shows homology with the subclass of thionins containing six cysteine residues of which crambin is a representative. The six-cysteine type thionin from radish displays in vitro antifungal activity against Fusarium culmorum. This activity is however substantially lower than that of the eight-cysteine type thionins from cereals.