Tissue-Specific Promoters for CRISPR Plant Genome Editing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Heritably modifying a plant genome to introduce desirable traits is challenging due to pleiotropic effects, where mutations can have both desirable and undesirable phenotypic impacts, and existing transgenic traits often impact the entire life cycle, making it difficult to control their transmission and expression.
Innovation Solution
The use of CRISPR/Cas systems for precise editing of nucleic acid sequences in plants, involving crossing transgenic plants with ubiquitously expressing and reproductive tissue-specific promoters linked to guide RNAs and Cas enzymes, allows for targeted mutations in specific tissues or developmental stages, enabling the reduction or elimination of gene function in a controlled manner.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If heritable genome editing is performed to introduce desirable traits, then the desired agronomic traits can be improved, but pleiotropic effects cause unwanted phenotypic impacts
Solution Approach 1:
The patent applies tissue-specific promoters to restrict CRISPR/Cas expression to particular plant tissues (e.g., roots, leaves, flowers) rather than systemically. This localizes the gene editing effect to specific organs where desirable traits are needed, preventing pleiotropic harmful effects in other tissues. For example, editing a gene in root tissue only affects root morphology, not above-ground traits.
Solution Approach 2:
The patent segments the plant life cycle into different stages (vegetative, reproductive, senescence) and applies tissue-specific promoters active only in specific stages. This temporal and spatial segmentation allows editing to occur only when and where needed, avoiding unwanted effects during other life phases.
2Reliability
If transgenic traits are introduced to improve plant characteristics, then desirable traits can be obtained, but the entire life cycle is impacted making transmission control difficult
Solution Approach 1:
The patent uses tissue-specific promoters that are inactive in reproductive tissues (pollen, ovules, seeds) to express CRISPR/Cas enzymes only in somatic tissues. This ensures that edited traits are not transmitted through germline inheritance, maintaining control over trait transmission while still achieving desirable somatic modifications.
Solution Approach 2:
The patent extracts the editing function from the germline by using promoters that exclude reproductive tissues. The CRISPR/Cas system is present in somatic cells but absent or inactive in gametes, effectively separating the editing function from the transmission function and enabling independent control of both.
3Manufacturing precision
If CRISPR/Cas systems are used for precise editing, then targeted mutations can be achieved, but the complexity of controlling expression in specific tissues increases
Solution Approach 1:
The patent employs tissue-specific promoters as intermediary regulatory elements that mediate between the CRISPR/Cas editing system and the plant's natural tissue differentiation program. These promoters act as switches that automatically activate editing only in tissues where the promoter is naturally active, simplifying control without requiring complex external regulation systems.
Solution Approach 2:
The tissue-specific promoters are derived from the plant's own genome and utilize the plant's endogenous regulatory mechanisms to control CRISPR/Cas expression. The system serves itself by using the plant's natural developmental cues (hormones, transcription factors) to determine when and where editing occurs, eliminating the need for external control systems.
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 approach enables the production of plants with desirable agronomic traits while minimizing unwanted effects by ensuring mutations occur only in specific tissues or stages, thereby controlling the expression and transmission of transgenic traits.
Implementation Method 1
the gRNA comprises a targeting sequence that hybridizes to a portion of at least one gene
Implementation Method 2
The edited mutations are usually inherited in the germline and necessarily impact an entire life cycle
Data Source
AI summary
Described are methods and materials for the genetic modification of plants by specific gene targeting and precise editing of nucleic acid sequences in a plant. The methods and materials provided herein enable one to edit the plant genome by design to control the expression of endogenous genes and/or control the transmission and expression of transgenic traits. Provided are also methods of producing plants having a desirable agronomic trait by crossing a transgenic plant expressing a gRNA with a plant expressing a Cas enzyme, and selecting a progeny plant having the desirable agronomic trait or a seed thereof.