title: Transgenic plants expressing cationic peptide chimeras exhibit broad-spectrum resistance to phytopathogens.
abstract: Here we describe a strategy for engineering transgenic plants with broad-spectrum resistance to bacterial and fungal phytopathogens. We expressed a synthetic gene encoding a N terminus-modified, cecropin-melittin cationic peptide chimera (MsrA1), with broad-spectrum antimicrobial activity. The synthetic gene was introduced into two potato (Solanum tuberosum L.) cultivars, Desiree and Russet Burbank, stable incorporation was confirmed by PCR and DNA sequencing, and expression confirmed by reverse transcription (RT)-PCR and recovery of the biologically active peptide. The morphology and yield of transgenic Desiree plants and tubers was unaffected. Highly stringent challenges with bacterial or fungal phytopathogens demonstrated powerful resistance. Tubers retained their resistance to infectious challenge for more than a year, and did not appear to be harmful when fed to mice. Expression of msrA1 in the cultivar Russet Burbank caused a striking lesion-mimic phenotype during leaf and tuber development, indicating its utility may be cultivar specific. Given the ubiquity of antimicrobial cationic peptides as well as their inherent capacity for recombinant and combinatorial variants, this approach may potentially be used to engineer a range of disease-resistant plants.
authors.affiliation: Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Osusky
authors.forename: G
authors.initials: G
authors.lastname: Zhou
authors.forename: L
authors.initials: L
authors.lastname: Osuska
authors.forename: R E
authors.initials: RE
authors.lastname: Hancock
authors.forename: W W
authors.initials: WW
authors.lastname: Kay
authors.forename: S
authors.initials: S
authors.lastname: Misra
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000871:Anthelmintics; D007113:Immunity, Innate / Q000235:genetics*; D008555:Melitten / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000235:genetics*; D010455:Peptides / Q000235:genetics*; D010641:Phenotype; D010935:Plant Diseases / Q000235:genetics; D030821:Plants, Genetically Modified; D010957:Plasmids / Q000378:metabolism; D017433:Protein Structure, Secondary; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D011198:Solanum tuberosum / Q000235:genetics; D014170:Transformation, Genetic
chemical_list: D000871:Anthelmintics; D010446:Peptide Fragments; D010455:Peptides; C111208:cecropin A(1-8)melittin(1-18); D008555:Melitten