Evaluation of transgenic 'Chardonnay' (Vitis vinifera) containing magainin genes for resistance to crown gall and powdery mildew

Transgenic Res. 2006 Feb;15(1):69-82. doi: 10.1007/s11248-005-4423-5.


Magainins, short peptides with broad-spectrum antimicrobial activity in vitro, were assayed for their ability to confer resistance to pathogens in transgenic grapevines. Embryogenic cell suspensions of 'Chardonnay' (Vitis vinifera L.) were co-transformed by microprojectile bombardment with a plasmid carrying the npt-II gene and a second plasmid harboring either a natural magainin-2 (mag2) or a synthetic derivative (MSI99) gene. Magainin genes and the marker gene were driven by Arabidopsis ubiquitin-3 and ubiquitin-11 promoters, respectively. A total of 10 mag2 and 9 MSI99 regenerated lines were studied by Southern blot hybridization, which showed 1-6 transgene integration events into the plant genome. Semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) revealed a variable range in transcription levels among mag2 and MSI99 lines. A positive correlation between number of integration events and transcription level was observed (p<0.05). Plants were acclimated and challenged in the greenhouse with either Agrobacterium vitis strains (bacterial crown gall pathogen) at 10(8) cfu/ml or Uncinula necator (fungal powdery mildew pathogen) at 10(5) conidia/ml for evaluation of disease resistance. A total of 6 mag2 and 5 MSI99 lines expressing the antimicrobial genes exhibited significant reductions of crown gall symptoms as compared to non-transformed controls. However, only two mag2 lines showed measurable symptom reductions in response to U. necator, but not strong resistance. Our results suggest that the expression of magainin-type genes in grapevines may be more effective against bacteria than fungi. Additional strategies to enhance transgene expression and the spectrum of resistance to grape diseases are suggested.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Antimicrobial Cationic Peptides / genetics*
  • Antimicrobial Cationic Peptides / metabolism
  • Arabidopsis / genetics
  • Blotting, Southern
  • Molecular Sequence Data
  • Peptides / genetics*
  • Peptides / physiology
  • Plant Tumors / genetics*
  • Plant Tumors / microbiology*
  • Promoter Regions, Genetic
  • Recombinant Proteins / genetics
  • Reverse Transcriptase Polymerase Chain Reaction
  • Rhizobium / pathogenicity
  • Vitis / genetics*
  • Vitis / metabolism
  • Vitis / microbiology


  • Antimicrobial Cationic Peptides
  • MSI-99 peptide
  • Peptides
  • Recombinant Proteins