Combining hexanoic acid plant priming with Bacillus thuringiensis insecticidal activity against Colorado potato beetle

Int J Mol Sci. 2013 Jun 6;14(6):12138-56. doi: 10.3390/ijms140612138.


Interaction between insect herbivores and host plants can be modulated by endogenous and exogenous compounds present in the source of food and might be successfully exploited in Colorado potato beetle (CPB) pest management. Feeding tests with CPB larvae reared on three solanaceous plants (potato, eggplant and tomato) resulted in variable larval growth rates and differential susceptibility to Bacillus thuringiensis Cry3Aa toxin as a function of the host plant. An inverse correlation with toxicity was observed in Cry3Aa proteolytic patterns generated by CPB midgut brush-border membrane vesicles (BBMV) from Solanaceae-fed larvae, being the toxin most extensively proteolyzed on potato, followed by eggplant and tomato. We found that CPB cysteine proteases intestains may interact with Cry3Aa toxin and, in CPB BBMV from larvae fed all three Solanaceae, the toxin was able to compete for the hydrolysis of a papain substrate. In response to treatment with the JA-dependent plant inducer Hexanoic acid (Hx), we showed that eggplant reduced OPDA basal levels and both, potato and eggplant induced JA-Ile. CPB larvae feeding on Hx-induced plants exhibited enhanced Cry3Aa toxicity, which correlated with altered papain activity. Results indicated host-mediated effects on B. thuringiensis efficacy against CPB that can be enhanced in combination with Hx plant induction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Bacillus thuringiensis / chemistry*
  • Bacillus thuringiensis Toxins
  • Bacterial Proteins / toxicity
  • Body Weight / drug effects
  • Caproates / pharmacology*
  • Coleoptera / drug effects*
  • Coleoptera / growth & development
  • Colorado
  • Cysteine Proteases / metabolism
  • Diet
  • Digestive System / drug effects
  • Digestive System / enzymology
  • Electrophoresis, Gel, Two-Dimensional
  • Endotoxins / toxicity
  • Feeding Behavior / drug effects
  • Hemolysin Proteins / toxicity
  • Host-Pathogen Interactions / drug effects
  • Insect Proteins / chemistry
  • Insect Proteins / metabolism
  • Insecticides / pharmacology*
  • Larva / drug effects
  • Larva / genetics
  • Mass Spectrometry
  • Molecular Sequence Data
  • Peptides / metabolism
  • Plant Growth Regulators / pharmacology
  • Proteolysis / drug effects
  • Sequence Alignment
  • Solanum tuberosum / parasitology*


  • Bacillus thuringiensis Toxins
  • Bacterial Proteins
  • Caproates
  • Endotoxins
  • Hemolysin Proteins
  • Insect Proteins
  • Insecticides
  • Peptides
  • Plant Growth Regulators
  • insecticidal crystal protein, Bacillus Thuringiensis
  • hexanoic acid
  • Cysteine Proteases