Transgenic Plants With Rhodococcus HPPD Enzyme Herbicide Tolerance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for developing plants tolerant to HPPD inhibitor herbicides, particularly those belonging to the triketones and pyrazolinates classes, are inadequate, as existing strategies do not provide sufficient tolerance to newer or diverse HPPD inhibitors, and there is a need for improved tolerance mechanisms.
Innovation Solution
Generation of transgenic plants containing genes encoding HPPD proteins from Rhodococcus species, specifically from strain RHA1, which are more resistant to HPPD inhibitors by modifying the amino acid sequence to enhance tolerance, allowing the plants to maintain enzymatic activity while being less sensitive to herbicides.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing HPPD proteins from plants or bacteria are used, then the plant can maintain basic enzymatic activity, but the plant does not achieve sufficient tolerance to newer HPPD inhibitor herbicides
Solution Approach 1:
The patent applies parameter changes by modifying specific amino acid residues in the HPPD protein sequence (positions 207-209, 248-252, 263-267, 287-291, 317-321, 354-358, 367-371, 380-384) to alter the enzyme's interaction with herbicides. These sequence variations change the binding characteristics of the HPPD enzyme, reducing affinity for HPPD inhibitor herbicides while maintaining catalytic function, thereby achieving herbicide tolerance.
Solution Approach 2:
The patent uses copying by transferring the modified HPPD gene from Rhodococcus bacteria into plant cells through transformation. The bacterial HPPD gene is inserted into the plant genome, allowing the plant to produce the modified enzyme protein that confers herbicide tolerance. This copying approach enables the acquisition of a functional trait from one organism to another.
2Reliability
If HPPD protein sequence is modified to enhance herbicide resistance, then tolerance to HPPD inhibitors is improved, but enzymatic activity may be compromised
Solution Approach 1:
The patent applies local quality by making specific targeted changes at particular positions in the HPPD protein sequence rather than random mutations. The modifications are localized to specific regions (positions 207-209, 248-252, 263-267, 287-291, 317-321, 354-358, 367-371, 380-384) that are known to interact with herbicides, while maintaining the overall protein structure and function. This localized approach ensures herbicide resistance without compromising enzymatic activity.
Solution Approach 2:
The patent applies partial action by introducing multiple specific amino acid variations at different positions in the HPPD protein. Rather than requiring complete sequence changes, partial modifications at key positions are sufficient to achieve herbicide tolerance. The multiple variations provided in the patent sequences (SEQ ID Nos: 4-7, 18-21) represent partial actions that collectively provide the desired resistance trait while preserving enzyme function.
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 transgenic plants exhibit increased tolerance to HPPD inhibitor herbicides, such as sulcotrione, mesotrione, and pyrasulfotole, maintaining enzymatic function and reducing sensitivity to post-emergence applications, thereby improving agronomic performance.
Implementation Method 1
The HPPDs are enzymes which catalyse the reaction in which para-hydroxyphenylpyruvate (abbreviated herein as HPP), a tyrosine degradation product, is transformed into homogentisate (abbreviated herein as HG)
Implementation Method 2
Generation of transgenic plants containing genes encoding HPPD proteins from Rhodococcus species, specifically from strain RHA1, which are more resistant to HPPD inhibitors by modifying the amino acid sequence
Data Source
AI summary
The present invention relates to nucleic acid sequences encoding a hydroxyphenylpyruvate dioxygenase (EC 1.13.11.27, abbreviated herein as HPPD) obtained from bacteria belonging to the genus Rhodococcus as well as the proteins encoded thereby, and to a chimeric gene which comprises such nucleic acid sequence, and to the use of such nucleic acid sequences, proteins or chimeric genes for obtaining plants which are tolerant to HPPD inhibitor herbicides.