Planta

, Volume 223, Issue 3, pp 392–406

Enhanced resistance to the rice blast fungus Magnaporthe grisea conferred by expression of a cecropin A gene in transgenic rice

  • María Coca
  • Gisela Peñas
  • Jorge Gómez
  • Sonia Campo
  • Cristina Bortolotti
  • Joaquima Messeguer
  • Blanca San Segundo
Original Article

Abstract

Cecropins are a family of antimicrobial peptides, which constitute an important key component of the immune response in insects. Here, we demonstrate that transgenic rice (Oryza sativa L.) plants expressing the cecropin A gene from the giant silk moth Hyalophora cecropia show enhanced resistance to Magnaporthegrisea, the causal agent of the rice blast disease. Two plant codon-optimized synthetic cecropin A genes, which were designed either to retain the cecropin A peptide in the endoplasmic reticulum, the ER-CecA gene, or to secrete cecropin A to the extracellular space, the Ap-CecA gene, were prepared. Both cecropin A genes were efficiently expressed in transgenic rice. The inhibitory activity of protein extracts prepared from leaves of cecropin A-expressing plants on the in vitro growth of M. grisea indicated that the cecropin A protein produced by the transgenic rice plants was biologically active. Whereas no effect on plant phenotype was observed in ER-CecA plants, most of the rice lines expressing the Ap-CecA gene were non-fertile. Cecropin A rice plants exhibited resistance to rice blast at various levels. Transgene expression of cecropin A genes was not accompanied by an induction of pathogenesis-related (PR) gene expression supporting that the transgene product itself is directly active against the pathogen. Taken together, the results presented in this study suggest that the cecropin A gene, when designed for retention of cecropin A into the endoplasmic reticulum, could be a useful candidate for protection of rice plants against the rice blast fungus M. grisea.

Keywords

Antifungal Cecropin A Oryza Rice blast fungus Transgenic rice 

Abbreviations

ER

endoplasmic reticulum

ICF

intercellular fluid

PR

pathogenesis related

Copyright information

© Springer-Verlag 2005

Authors and Affiliations

  • María Coca
    • 1
    • 2
  • Gisela Peñas
    • 1
    • 3
  • Jorge Gómez
    • 1
    • 2
  • Sonia Campo
    • 1
    • 2
  • Cristina Bortolotti
    • 1
    • 2
  • Joaquima Messeguer
    • 1
    • 3
  • Blanca San Segundo
    • 1
    • 2
  1. 1.Laboratorio de Genética Molecular VegetalConsorcio CSIC-IRTABarcelonaSpain
  2. 2.Departamento de Genética MolecularInstituto de Biología Molecular de Barcelona, CSICBarcelonaSpain
  3. 3.Departamento de Genética VegetalIRTA Centro de CabrilsBarcelonaSpain

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