Engineered multidomain cysteine protease inhibitors yield resistance against western flower thrips (Franklinielia occidentalis) in greenhouse trials

Research output: Contribution to journalArticle


Western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripiclae), cause very large economic damage on a variety of field and greenhouse crops. In this study, plant resistance against thrips was introduced into transgenic potato plants through the expression of novel, custom-made, multiclomain protease inhibitors. Representative classes of inhibitors of cysteine and aspartic proteases [kininogen domain 3 (K), stefin A (A), cystatin C (C), potato cystatin (P) and equistatin (EIM)] were fused into reading frames consisting of four (K-A-C-P) to five (EIM-K-A-C-P) proteins, and were shown to fold into functional inhibitors in the yeast Pichia pastoris. The multiclomain proteins were expressed in potato and found to be more resistant to degradation by plant proteases than the individual domains. In a time span of 14-16 days, transgenic potato plants expressing EIMKACP and KACP at a similar concentration reduced the number of larvae and adults to less than 20% of the control. Leaf damage on protected plants was minimal. Engineered multiclomain cysteine protease inhibitors thus provide a novel way of controlling western flower thrips in greenhouse and field crops, and open up possibilities for novel insect resistance applications in transgenic crops.


Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Medicinal Chemistry
  • Pharmacology and Toxicology


  • protease inhibitor, Frankliniella occidentalis, insect resistance, thrips, transgenic plants
Original languageEnglish
Pages (from-to)449-458
JournalPlant Biotechnology Journal
Issue number5
StatePublished - 2004