New insect resistance option for GM cotton
A combination of serine protease inhibitors (PI) from ornamental tobacco ( Nicotiana alata) and potato are effective against major cotton insect pests. The finding has the potential to provide an alternative to the Bt Cry (crystal toxin) or Vip (vegetative insecticidal protein) insect resistance traits currently available, scientists say. Researchers from the Australian agricultural biotechnology company, Hexima (Melbourne, Victoria) and Australia’s La Trobe University (Melbourne) have found that a protease inhibitor from N alata, NaPI, targets two major digestive enzymes, trypsin and chymotrypsin, in the larvae of cotton bollworms ( Helicoverpa armigera) and budworms ( H punctigera), It “dramatically reduces” growth and development in most but not all larvae. This was because some H punctigera larvae had high levels of chymotrypsin activity resistant to inhibition by NaPI.