Coexpression of potato type I and II proteinase inhibitors gives cotton plants protection against insect damage in the field

• Published in: Proceedings of the National Academy of Sciences - PNAS 2010-08, Vol.107 (34), p.15011-15015
• Main Authors: Dunse, K. M., Stevens, J. A., Lay, F. T., Gaspar, Y. M., Heath, R. L., Anderson, M. A., Clarke, Adrienne
• Format: Article
• Language: English
• Subjects: Animals; Biological Sciences; Chymotrypsin; Chymotrypsin - antagonists & inhibitors; Cotton; Crop protection; Defense mechanisms; Digestive enzymes; Digestive tract; Enzymes; Gene Expression; Genes, Plant; Genetics; Gossypium - genetics; Gossypium - metabolism; Gossypium - parasitology; Helicoverpa punctigera; Insect biochemistry; Insect genetics; Insect larvae; Insect pests; Insect Proteins - antagonists & inhibitors; Insects; Larva - drug effects; Larva - growth & development; Larval development; Lepidoptera; Molecular Sequence Data; Moths - drug effects; Moths - growth & development; Moths - pathogenicity; Nicotiana alata; Pest Control, Biological - methods; Pests; Plant Diseases - parasitology; Plant Diseases - prevention & control; Plant protection; Plant Proteins - genetics; Plant Proteins - metabolism; Plant Proteins - pharmacology; Plants; Plants, Genetically Modified; Potatoes; Protease inhibitors; Protease Inhibitors - metabolism; Protease Inhibitors - pharmacology; Proteinase inhibitors; Serine proteinase; Solanum tuberosum; Solanum tuberosum - genetics; Solanum tuberosum - metabolism; Tissues; Tobacco; Transgenic insects; Transgenic plants; Trypsin
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.1009241107

Potato type I and II serine protease inhibitors are produced by solanaceous plants as a defense mechanism against insects and microbes. Nicotiana alata proteinase inhibitor (NaPI) is a multidomain potato type II inhibitor (pin II) that is produced at high levels in the female reproductive tissues of the ornamental tobacco, Nicotiana alata. The individual inhibitory domains of NaPI target the major classes of digestive enzymes, trypsin and chymotrypsin, in the gut of lepidopteran larval pests. Although consumption of NaPI dramatically reduced the growth and development of a major insect pest, Helicoverpa punctigera, we discovered that surviving larvae had high levels of chymotrypsin activity resistant to inhibition by NaPI. We found a potato type I inhibitor, Solanum tuberosum potato type I inhibitor (StPin1A), was a strong inhibitor of the NaPI-resistant chymotrypsin activity. The combined inhibitory effect of NaPI and StPin1A on H. armigera larval growth in the laboratory was reflected in the increased yield of cotton bolls in field trials of transgenic plants expressing both inhibitors. Better crop protection thus is achieved using combinations of inhibitors in which one class of proteinase inhibitor is used to match the genetic capacity of an insect to adapt to a second class of proteinase inhibitor.