Transgenic Corn Event 2A-7 for Stable Lepidopteran Resistance
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Solution Overview
Problem
Current methods for controlling corn pests, particularly lepidopteran pests, rely heavily on chemical pesticides, which disrupt ecological balance and cause environmental pollution, while transgenic corn plants with randomly integrated insect resistance genes face issues of unpredictable gene expression and potential lethality due to random insertion events.
Innovation Solution
Development of a transgenic corn event 2A-7 with stably integrated Cry1Ab and Cry2Ab proteins, flanked by specific 5′- and 3′-flanking regions, providing resistance to lepidopteran pests and potentially herbicides, with methods for detecting the event through specific primer pairs and probes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If chemical pesticides are used to control corn pests, then pest damage is reduced, but ecological balance is disrupted and environmental pollution occurs
Solution Approach 1:
The patent replaces chemical pesticide application with a biological control mechanism by introducing insect resistance genes (Cry1Ab and Cry2Ab) into corn plants. These genes encode proteins that are toxic to specific insect pests but harmless to humans and the environment, thereby substituting chemical mechanisms with biological mechanisms for pest control.
Solution Approach 2:
The transgenic corn plants produce their own insecticidal proteins through the expressed Cry1Ab and Cry2Ab genes, enabling self-protection against pest attacks. This eliminates the need for external chemical pesticide applications and allows the plant to autonomously defend itself against insects.
2Reliability
If insect resistance genes are randomly integrated into corn genome, then insect resistance is achieved, but gene expression becomes unpredictable and plant lethality may occur
Solution Approach 1:
The patent employs a carefully designed expression cassette structure with specific promoter elements (such as the polyhedrin promoter) and regulatory sequences that are prepared in advance. This preliminary design ensures that when the genes are integrated into the corn genome, they will be properly expressed without requiring precise control of the integration site, thereby preventing plant lethality while ensuring reliable insect resistance.
Solution Approach 2:
The patent optimizes various parameters of the transgene construct including the choice of promoter strength, gene copy number, and structural organization of the expression cassette. By adjusting these parameters, the patent achieves stable and predictable expression of insect resistance proteins while minimizing the risk of negative effects from random integration events.
3Manufacturing precision
If multiple corn events are screened to identify good events, then optimal gene expression is achieved, but detection and identification becomes more difficult
Solution Approach 1:
The patent extracts and utilizes the unique flanking sequences that naturally occur at the boundaries of the integrated transgene construct in event 2A-7. These flanking sequences serve as unique molecular fingerprints that allow for the specific detection and identification of this event through PCR amplification, thereby simplifying the identification process while maintaining the ability to screen for optimal expression events.
Solution Approach 2:
The patent employs specific PCR primers and probes as intermediary tools that target unique sequences within or adjacent to the transgene construct. These intermediaries facilitate the detection and differentiation of event 2A-7 from other transgenic events or non-transgenic plants, making the identification process more straightforward despite the need to screen multiple events for optimal performance.
Data Source
AI summary
Provided are a transgenic corn event 2A-7, and corn plants or parts, seeds, cells, or progenies thereof containing nucleic acid molecules for diagnosing the corn event. The event shows resistance to lepidopteran insect infestation. Further provided are a method for detecting the presence of nucleic acid molecules unique to the corn event in a sample, and a probe and a primer for detecting the presence of the corn event in the sample. Further provided is a method for producing corn plants and seeds containing the nucleic acid molecules for the corn event.