Brachypodium Metallothionein Promoter for Root-Specific Transgene Expression

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Solution Overview

Problem

Current plant transformation technologies face challenges in achieving consistent and tissue-specific expression of multiple transgenes, leading to gene silencing and rearrangements due to repetitive promoter elements, which affects the performance of transgenic plants.

Innovation Solution

The use of a Brachypodium distachyon metallothionein-like gene promoter, with at least 90% sequence identity to SEQ ID NO:1, operably linked to a polylinker or transgene, drives specific expression in below-ground tissues and is compatible with various plant species, including maize, wheat, and Arabidopsis, to confer traits like insecticidal resistance and herbicide tolerance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional plant transformation technologies use repetitive promoter elements to drive expression of multiple transgenes, then transgenic plants can be produced with desirable traits, but gene silencing and rearrangements occur reducing expression consistency

Engineering Contradiction:

Improvetransgene expression levelVSAvoidexpression consistency

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The promoter is divided into multiple functional modules including a core promoter region, upstream regulatory elements, and downstream elements. This segmentation allows optimization of each region independently to enhance expression while maintaining stability across multiple transgenes.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The promoter sequence is modified through specific parameter changes including nucleotide substitutions and additions of regulatory motifs. These changes optimize transcription factor binding sites and enhance promoter activity without causing silencing, thereby improving both productivity and reliability.

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If conventional promoters are used to drive transgene expression in specific tissues, then tissue-specific expression can be achieved, but expression levels are insufficient for robust trait expression

Engineering Contradiction:

Improvetissue-specific expressionVSAvoidexpression level

Core Design Contradiction:

Adaptability or versatilityVSProductivity

Solution Approach 1:

The promoter combines tissue-specific regulatory elements from multiple sources including root-specific, shoot-specific, and stress-responsive elements. This merging creates a composite promoter that maintains tissue-specificity while achieving high expression levels through synergistic interaction of multiple regulatory motifs.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The promoter functions as a composite genetic element incorporating diverse regulatory sequences, transcription factor binding sites, and enhancer regions. This composite structure integrates multiple functions (tissue-specificity, high expression, stress responsiveness) into a single promoter unit, resolving the contradiction between specificity and productivity.

Inventive Principle:

Principle #40Composite materials

Data Source

PatentUS10443067B2Root-preferred promoter from a brachypodium distachyon metallothionein-like gene

Publication Date: 2019.10.15 CORTEVA AGRISCIENCE LLC

AI summary

This disclosure concerns compositions and methods for promoting transcription of a nucleotide sequence in a plant or plant cell, employing a promoter from a Brachypodium distachyon metallothionein-like gene (mtl). Some embodiments relate to a promoter from a Brachypodium distachyon metallothionein-like gene (mtl) that functions in plants to promote transcription of operably linked nucleotide sequences.