Theoretical and Applied Genetics (2000) 101, 519-526

S. Marchetti, M. Delledonne, C. Fogher, C. Chiabà, F. Chiesa, F. Savazzini and A. Giordano (2000)
Soybean Kunitz, C-II and PI-IV inhibitor genes confer different levels of insect resistance to tobacco and potato transgenic plants
Theoretical and Applied Genetics 101 (4), 519-526
Abstract: In modern, highly intensive agriculture, the control of insect pests is basically achieved with the application of chemical pesticides. Heavy reliance on this sole strategy is associated with several drawbacks, and the development of alternative or complementary methods to chemical control is desirable. In this work, three soybean genes (KTi₃, C-II and PI-IV) coding for serine proteinase inhibitors were isolated by PCR and transferred to Agrobacterium tumefaciens EHA 105, which in turn was used for transforming tobacco leaf and potato tuber discs. Biochemical assays confirmed that transgenic plants synthesized serine proteinase inhibitors; rates of expression varied among plants. The level of insect resistance (tested with Spodoptera littoralis Boisduval) was particularly high in tobacco, where many plants caused the death of all larvae. In potatoes, larval mortality was much less frequently achieved, but the results were still encouraging in that larval weight gain was reduced by 50% in the presence of adequate amounts of inhibitor. When 8-day-old larvae were fed different KTi₃-expressing tobacco plants, a highly significant (P<0.01) correlation was observed between inhibitor content and larval live weight. Larval weight gain was found to be dependent on midgut proteolytic activity. On the basis of the evidence collected, it is suggested that further work is required to identify more specific inhibitors for the main proteinases of the target insect.
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Link to article at publishers website
Database assignments for author(s): Massimo Delledonne

Research topic(s) for pests/diseases/weeds:
resistance/tolerance/defence of host

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Spodoptera littoralis	Potato (Solanum tuberosum)
	Spodoptera littoralis	Tobacco (Nicotiana tabacum)