Genetic Modification of Plants to Produce Biopesticides: Chitinase

In a recent post, I mentioned the importance of identifying  genes and proteins besides Bacillus thuringiensis (Bt) that can be used in the fight against crop pests. One such protein is chitinase.

Chitinase (pronounced ′kītən′ās) is an enzyme that breaks down the protein chitin. Chitin is an important component of insect exoskeletons and fungal cell walls. Functionally, it helps the insect or fungus retain its structure. Destroy the chitin, and the insect or fungus dies.

Scientists from the Rao laboratory at the University of Napoli hypothesized that a plant that made its own chitinase could protect itself against pests. They generated genetically engineered (GE) plants that produced chitinase, then tested the effect of the chitinase-producing GE plants on fungi and tobacco budworm larvae.

Tobacco budworm (Heliothis virescens)

The results, published in a 2008 article in Transgenic Research, showed reduced fungal growth and abnormally slow weight gain in the insect larvae after they ingested the plants. This suggests that chitinase-producing GE plants protect themselves against damage from fungi and insect larvae better than non-GE plants.

In a future article, I will report on research which suggests that combining TMOF and chitinase improves crop protection against insect pests.

Corrado, G, Arciello, A, Fanti, P, Fiandra, L, Garonna, A, Diglio, MC, Lorito, M, Giordana, B, Pennacchio, F, Rao, R. 2008. The chitinase A from the baculovirus AcMNPV enhances resistance to both fungi and herbivorous pests in tobacco. Transgenic Research 17: 557 – 571, DOI: 10.1007/s11248-007-9129-4.

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