Disclosed is an isolated artificially modified solanaceous Class II defensin polypeptide with a loop region (Loop 1B) between a first Beta-strand and an Alpha-helix at its N-terminal end portion and having anti-fungal activity, and wherein said Loop 1B is replaced by an exogenous Loop 1B amino acid sequence, said polypeptide having at least 70% similarity to SEQ ID NO:52 after optimal alignment; wherein SEQ ID NO: 52 is as disclosed in the specification.