Abstract: This invention describes methods, transgenic plants and transgenic microorganisms for the biosynthesis of halogenated natural products, where the halogenation is substrate and regiospecific. In particular, this invention relates to the use of halogenated metabolites, produced by the method of the invention, for the protection of host organisms against pathogens, more particularly, to the protection of plants against phytopathogens. In this aspect, the invention provides transgenic plants with enhanced resistance to phytopathogens, and biocontrol organisms with enhanced biocontrol properties.