Cry1Fa and Cry1Ca Protein Combination for Insect Resistance Management
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Solution Overview
Problem
The development of resistance in insect populations to single insecticidal proteins used in transgenic plants poses a challenge for maintaining the effectiveness of Bt-based insect resistance traits, as cross-resistance can occur when proteins compete for the same receptor, limiting the spectrum of control and necessitating refuge areas to manage resistance.
Innovation Solution
The use of Cry1Fa and Cry1Ca proteins, which do not compete for binding sites in fall armyworm and sugarcane borer insects, allowing for their co-production in plants to create a high-dose IRM stack that delays resistance development and expands the insecticidal spectrum without cross-resistance, potentially reducing the need for refuge areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a single Bt protein is deployed in transgenic plants, then the insecticidal effect is strong and simple to implement, but insect populations develop resistance quickly and cross-resistance limits the spectrum of control
Solution Approach 1:
The patent combines Cry1Fa and Cry1Ca proteins in a single transgenic plant variety to create a pyramided trait. This merging of two different Bt proteins with distinct receptor binding specificities delays resistance development while maintaining strong insecticidal activity against multiple pest species including fall armyworm and European corn borer.
Solution Approach 2:
The combined Cry1Fa/Cry1Ca stack provides multi-functionality by controlling multiple pest species (fall armyworm, European corn borer, sugarcane borer) and serving dual purposes: maintaining high insecticidal effectiveness while delaying resistance development. The system acts as both a primary control mechanism and a resistance management tool.
2Adaptability or versatility
If Bt proteins that compete for the same receptor are used, then the insecticidal spectrum is narrowed, but resistance management becomes more difficult due to cross-resistance
Solution Approach 1:
The patent utilizes the different local binding specificities of Cry1Fa and Cry1Ca proteins to insect gut receptors. Cry1Fa binds to one receptor type while Cry1Ca binds to a different receptor type, allowing each protein to exert its insecticidal effect independently on different pest populations without inducing cross-resistance.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This combination of Cry1Fa and Cry1Ca proteins effectively controls fall armyworm and European corn borer populations, delaying resistance development and enhancing pest control in corn plants, thereby reducing the requirement for refuge areas and maintaining the efficacy of insecticidal proteins.
Implementation Method 1
The key predictor of lack of cross resistance inherent in this approach is that the insecticidal proteins do not compete for receptors in a sensitive insect species.
Implementation Method 2
The utility of receptor-mediated binding in identifying insecticidal proteins likely to not exhibit cross resistance has been suggested
Data Source
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AI summary
The subject invention includes methods and plants for controlling lepidopteran insects, said plants comprising a CrylFa insecticidal protein and a Cry1Ca insecticidal protein, in combination, to delay or prevent development of resistance by the insect(s).