Ribozyme Mitochondrial RNA Cleavage for Plant Male Sterility

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Solution Overview

Problem

Current methods for inducing cytoplasmic male sterility in plants are inefficient, labor-intensive, and species-dependent, with existing techniques such as castration and genetic engineering having limitations, and there is a lack of effective tools for manipulating mitochondrial gene expression in plants.

Innovation Solution

Development of a ribozyme-based antisense strategy using a polyribonucleotide comprising a hammerhead ribozyme targeted against mitochondrial RNA, associated with a valine-aminoacylable tRNA-like structure, to specifically cleave target RNAs in plant mitochondria, facilitating cytoplasmic male sterility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional castration methods are used to induce male sterility, then male sterility can be achieved, but the process becomes labor-intensive and expensive

Engineering Contradiction:
Improvemale sterility inductionVSAvoidlabor efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent replaces mechanical castration methods with a biochemical approach using ribozyme-based RNA cleavage. The ribozyme construct targets and degrades specific mitochondrial mRNAs, inducing male sterility through molecular mechanisms rather than physical removal of organs, thereby eliminating labor-intensive manual operations.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the fundamental mechanism from physical/causal intervention to genetic/molecular intervention. By introducing a ribozyme construct that modifies RNA expression parameters, the system achieves male sterility through changes in gene expression rather than physical or chemical castration, improving both reliability and efficiency.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If chemical castration is used in wheat, then male sterility can be induced, but yield losses occur in seed production

Engineering Contradiction:
Improvemale sterility inductionVSAvoidseed yield
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent replaces chemical castration with a molecular biology-based approach. The ribozyme construct specifically targets and degrades mitochondrial mRNAs through RNA cleavage, avoiding the use of chemical gametocides that cause yield losses, while maintaining reliable male sterility induction.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent applies local quality by targeting specific mitochondrial mRNAs with the ribozyme construct. The RNA cleavage is localized to specific gene expressions within the mitochondria, allowing precise control over which proteins are degraded, thereby achieving male sterility without the broad phytotoxic effects and yield losses associated with chemical castration.

Inventive Principle:
Principle #3Local quality

3Reliability

If chemical gametocides are used for castration, then male sterility can be achieved, but phytotoxic effects and health dangers arise

Engineering Contradiction:
Improvemale sterility inductionVSAvoidphytotoxic effects
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces chemical gametocides with a biological approach using ribozyme-based RNA cleavage. The system uses molecular mechanisms to degrade specific mRNAs, eliminating the need for harmful chemicals that cause phytotoxic effects and health dangers, while maintaining effective male sterility induction.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent converts the natural RNA degradation pathway into a beneficial tool. By designing a ribozyme construct that exploits the cell's existing RNA processing mechanisms, the system achieves male sterility through controlled molecular interactions rather than external harmful chemicals, turning a potential harm into a useful biological process.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

4Reliability

If conventional genetic engineering methods are used to induce male sterility, then male sterility can be achieved, but the methods are species-dependent and lack universality

Engineering Contradiction:
Improvemale sterility inductionVSAvoidmethod applicability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent achieves universality by designing a ribozyme-based system that can be applied across different plant species. The core mechanism of RNA cleavage and mitochondrial targeting is conserved across plants, allowing the same basic construct design to induce male sterility in various species without requiring species-specific optimization, thereby improving adaptability and versatility.

Inventive Principle:
Principle #6Universality (Multi-functionality)

5Reliability

If mitochondrial RNA cleavage is performed, then cytoplasmic male sterility can be induced, but specific tools for manipulating mitochondrial gene expression are lacking

Engineering Contradiction:
Improvecytoplasmic male sterility inductionVSAvoidtool availability
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces a ribozyme construct as an intermediary tool that facilitates mitochondrial RNA manipulation. The construct acts as a mediator between the nuclear genome and mitochondrial genome, enabling controlled RNA cleavage in mitochondria through a modular system that combines nuclear-encoded ribozyme with mitochondrial targeting sequences, thereby providing a versatile tool for manipulating mitochondrial gene expression.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 approach allows for efficient and specific cleavage of mitochondrial RNAs, effectively inducing cytoplasmic male sterility in plants, overcoming the limitations of existing methods by providing a universal and precise genetic tool for manipulating mitochondrial gene expression.

Implementation Method 1

a ribozyme-based antisense strategy using a polyribonucleotide comprising a hammerhead ribozyme targeted against mitochondrial RNA, to specifically cleave target RNAs in plant mitochondria

Methodology Applied
Scientific EffectRibozyme catalysis: Enzyme

Data Source

PatentEP2334796B1Importation of a ribozyme into vegetable mitochondria by a pseudo-trna that can be aminoacylated by valine
Publication Date: 2015.03.04 CENT NAT DE LA RECH SCI (C N R S)
  • EP2334796B1 patent drawingFigure 1~2
  • EP2334796B1 patent drawingFigure 3~4
  • EP2334796B1 patent drawingFigure 5A~6

AI summary

The present invention relates to a polyribonucleotide including a hammerhead trans-ribozyme directed against a plant mitochondrial RNA and a structure in the form of tRNA that can be aminoacylated by valine, and to the use thereof in plants in particular for inducing cytoplasmic male sterility.