The present invention provides amino acid molecules derived from Nicotiana alata. The present invention contemplates the use of nucleic acids encoding such amino acid molecules in the generation of transgenic plants having resistance or at least reduced sensitivity to plant pests including insects, microorganisms, fungi and/or viruses. The transgenic plants provided by the present invention include monocotyledonous and dicotyledonous plants, and particularly include crop plants and ornamental flowering plants.