Delta-endotoxin gene mutations for insecticidal activity
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Solution Overview
Problem
There is a continuous need for new forms of pesticidal toxins to control insect pests effectively in agriculture, as existing methods may not fully address the devastation caused by insects and may not improve crop yields sufficiently.
Innovation Solution
The development of novel genes encoding pesticidal proteins, specifically delta-endotoxins, which can be used to transform bacteria and plants to confer pest resistance or tolerance, including the use of nucleic acid molecules, vectors, and host cells to produce organisms with enhanced pest resistance, and the generation of altered proteins with improved pesticidal activity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If existing pesticidal methods are used, then current pest control is maintained, but crop yield improvement is insufficient
Solution Approach 1:
The patent modifies the crystal protein structure by introducing point mutations (e.g., A181P, V201L, D229N substitutions) to alter the toxin's properties. These parameter changes in the protein sequence enhance insecticidal activity while maintaining safety, directly addressing the need for improved pest control effectiveness and crop yield
Solution Approach 2:
The invention creates composite pesticidal compositions by combining modified crystal proteins with other agents such as plant extracts, oils, or adjuvants. This composite approach enhances the overall pesticidal activity and provides synergistic effects that improve both pest control reliability and crop productivity
2Reliability
If new pesticidal toxins are developed, then pest control effectiveness is improved, but environmental safety may be compromised
Solution Approach 1:
The patent introduces specific localized mutations at particular positions (e.g., residues 181, 201, 229) within the crystal protein structure. These localized changes enhance insecticidal activity at specific binding sites while leaving other regions unchanged, thereby maintaining environmental safety and specificity to target pests
Solution Approach 2:
The invention utilizes the natural toxicity of crystal proteins against insects and redirects it through controlled mutagenesis to enhance specificity. The modified toxins become more effective against target pests while reduced toxicity toward non-target organisms, converting the potential harm into beneficial selective pest control
3Reliability
If crystal proteins are ingested by insects, then toxic activity is activated, but the activation process requires specific digestive conditions
Solution Approach 1:
The patent performs preliminary mutagenesis on the crystal protein to pre-optimize its stability and activation characteristics. The modified proteins are engineered in advance to maintain stability during ingestion and to be efficiently activated by a broader range of digestive conditions, reducing the need for highly specific digestive tract conditions
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
The novel pesticidal proteins effectively kill or impair insect pests, enhancing crop resistance and yield by providing a sustainable and environmentally friendly means of pest control.
Implementation Method 1
This toxin binds to apical brush border receptors in the midgut of the target larvae and inserts into the apical membrane creating ion channels or pores, resulting in larval death
Implementation Method 2
The ingested protoxin is hydrolyzed by proteases in the insect digestive tract to an active toxic molecule
Data Source
AI summary
Compositions and methods for conferring lepidoptericidal activity to bacteria, plants, plant cells, tissues and seeds are provided. Compositions comprising a coding sequence for the Axmi226 toxin polypeptide are provided. The Axmi226 coding sequences can be used in DNA constructs or expression cassettes for transformation and expression in plants and bacteria. Compositions also comprise transformed bacteria, plants, plant cells, tissues, and seeds. In particular, isolated Axmi226 toxin nucleic acid molecules are provided. Additionally, amino acid sequences corresponding to the Axmi226 polynucleotides are encompassed, and antibodies specifically binding to those amino acid sequences. In particular, the present invention provides for isolated nucleic acid molecules comprising nucleotide sequences encoding the amino acid sequence shown in SEQ ID NO:19 and 20, or the nucleotide sequence set forth in SEQ ID NO:4, as well as variants and fragments thereof.