Non-Transgenic LeExp1 Mutations for Delayed Tomato Softening

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Solution Overview

Problem

The tomato industry faces challenges in delivering vine-ripened tomatoes that remain firm without the usual post-harvest softening, which reduces shelf life, as traditional breeding methods are labor-intensive and may transfer undesirable traits, while transgenic methods are not universally accepted by consumers.

Innovation Solution

Creating non-transgenic tomato plants with induced mutations in the LeExp1 gene using chemical mutagenesis and PCR techniques to reduce post-harvest softening, thereby delaying fruit softening without genetic engineering.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If traditional breeding methods are used to develop tomato varieties with delayed post-harvest softening, then fruit firmness may be improved, but the process is labor-intensive and time-consuming with potential transfer of undesirable traits

Engineering Contradiction:
Improveshelf lifeVSAvoidbreeding process complexity
Core Design Contradiction:
Duration of action of stationary objectVSEase of manufacture

Solution Approach 1:

The invention changes the genetic parameter of the LeExp1 gene through induced mutations to alter the expression level of expansin proteins. By modifying specific nucleotide sequences in the LeExp1 gene, the patent achieves delayed post-harvest softening without the complexities of traditional breeding, directly changing the genetic parameter to achieve the desired phenotype.

Inventive Principle:
Principle #35Parameter changes

2Duration of action of stationary object

If transgenic methods are used to modify LeExp1 expression, then post-harvest softening can be controlled, but consumer acceptance is reduced due to genetic engineering concerns

Engineering Contradiction:
Improveshelf lifeVSAvoidconsumer rejection
Core Design Contradiction:
Duration of action of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The invention extracts and eliminates the foreign DNA element from the modification process. By using induced mutations that result in non-transgenic plants, the patent removes the transgenic component while retaining the beneficial effect of delayed softening, thereby addressing consumer concerns about genetic engineering.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention converts the potential harm of genetic modification into a benefit by using induced mutations that mimic natural variation. The mutagenesis process, which could be seen as harmful, is used to create beneficial mutations in the LeExp1 gene that delay softening without requiring transgenic approaches, thus turning a potentially controversial method into an acceptable solution.

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

3Reliability

If LeExp1 expression is increased to promote vine-ripening, then fruit quality improves, but post-harvest softening is accelerated

Engineering Contradiction:
Improvefruit qualityVSAvoidshelf life
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The invention applies local quality by specifically modifying the LeExp1 gene to achieve differential expression patterns. Through induced mutations, the patent creates variants where expansin activity is modulated in a controlled manner, allowing vine-ripening quality to be maintained while post-harvest softening is delayed, thus applying different functional qualities to different stages of fruit development.

Inventive Principle:
Principle #3Local quality

Data Source

PatentUS9399772B2Tomatoes that soften more slowly post-harvest due to non-transgenic alterations in an expansin gene
Publication Date: 2016.07.26 ARCADIA BIOSCIENCES INC

AI summary

A series of independent human-induced non-transgenic mutations found in an expansin gene (LeExp1) of tomato; tomato plants having these mutations in their LeExp1 genes; and a method of creating and identifying similar and/or additional mutations in the LeExp1 gene by screening pooled and/or individual tomato plants. The tomato plants of the present invention exhibit fruit that soften more slowly post-harvest without having the inclusion of foreign nucleic acids in their genomes.