Antibiotic activities of peptides, hydrogen peroxide and peroxynitrite in plant defence

Genes encoding plant antibiotic peptides show expression patterns that are consistent with a defence role. Transgenic over-expression of defence pepti de genes is potentially useful to engineer resistance of plants to relevant pathogens. Pathogen mutants that are sensitive to plant peptides in vitro have been obtained and a decrease of their virulence in planta has been obs erved, Which is consistent with their hypothetical defence role. A similar approach has been followed to elucidate the potential direct anti-microbial role of hydrogen peroxide, Additionally, a scavenger of peroxynitrite has been used to investigate its involvement in plant defence, (C) 2001 Publish ed by Elsevier Science B.V. on behalf of the Federation of European Biochem ical Societies.