HT Gene Modulation for Self-Compatible Diploid Potato Breeding

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Solution Overview

Problem

Diploid potato breeding is hindered by gametophytic self-incompatibility (GSI) systems, which cause self-pollen rejection through S-RNase-mediated pollen RNA degradation, limiting the development of inbred lines with desirable traits like yield, tuber quality, and disease resistance.

Innovation Solution

Modulation of HT gene activity in diploid potatoes and other Solanaceae species using genetic techniques such as CRISPR-Cas9 to induce, increase, decrease, or repress self-incompatibility by incorporating sense or antisense nucleic acids, or using gene editing to alter HT gene sequences, thereby reducing or eliminating self-incompatibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If GSI system is present in diploid potatoes, then self-pollen rejection occurs through S-RNase-mediated degradation, but this severely limits the ability to develop inbred lines

Engineering Contradiction:
Improveself-pollen rejection reliabilityVSAvoidinbred line development
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent extracts and removes the S-RNase gene from the diploid potato genome through genetic modification techniques. By eliminating this specific gene responsible for self-incompatibility, the plant loses its ability to reject self-pollen, thereby enabling inbred line development without compromising the overall reliability of the GSI system in maintaining species integrity

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the genetic parameter of the S-RNase gene by introducing mutations, deletions, or suppressor genes that alter its expression or function. This parameter change transforms the plant from self-incompatible to self-compatible state, resolving the contradiction between maintaining reliable self-pollen rejection and enabling inbred line development

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If diploid potatoes are self-compatible, then inbred lines can be developed, but reliability of self-compatibility in succeeding generations is unreliable

Engineering Contradiction:
Improveinbred line developmentVSAvoidself-compatibility expression stability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies preliminary genetic modification to establish stable self-compatible lines before breeding programs begin. By pre-modifying the genome to eliminate or suppress S-RNase function, the self-compatible trait is fixed in the genetic makeup, ensuring reliable expression in succeeding generations rather than relying on unstable phenotypic variation

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses molecular markers and genomic copying techniques to identify and propagate specific genetic modifications that confer stable self-compatibility. By copying and propagating the modified genetic material through selective breeding, the reliable expression of self-compatibility is maintained across generations

Inventive Principle:
Principle #26Copying

3Adaptability or versatility

If tetraploidy and heterozygosity are present in cultivated potato, then genetic diversity is maintained, but fixation of desirable alleles in new cultivars is hindered

Engineering Contradiction:
Improvegenetic diversityVSAvoidallele fixation speed
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent segments the complex tetraploid genome into manageable units by developing diploid inbred lines with fixed alleles. This segmentation allows researchers to work with simpler, more manageable genetic systems where allele fixation is achievable, while still maintaining overall genetic diversity through the creation of multiple distinct inbred lines that can be combined in hybrid programs

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent inverts the conventional approach by first creating fixed diploid inbred lines and then using them to generate hybrid varieties, rather than working directly with tetraploid heterogeneous populations. This inversion accelerates allele fixation in the diploid background, and the fixed alleles can then be combined in predictable ways to create new cultivars with desired traits

Inventive Principle:
Principle #13The other way round (Inversion)

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

Enables the creation of self-compatible diploid potatoes and other Solanaceae species, facilitating the development of hybrid plants and inbred lines with improved agronomic traits and genetic understanding.

Implementation Method 1

Applicants have a targeted knock-out of HT genes in self-incompatibility potato lines using Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated systems (CRISPR/Cas9) technology

Methodology Applied
Scientific EffectCRISPR-Cas9 genome editing:

Implementation Method 2

causing rejection of self-pollen through the S-RNase-mediated degradation of pollen RNA

Methodology Applied
Scientific EffectRNA degradation:

Data Source

PatentUS12534737B2Overcoming self-incompatibility in diploid plants for breeding and production of hybrids through modulation of HT
Publication Date: 2026.01.27 BOARD OF TRUSTEES OPERATING MICHIGAN STATE UNIV

AI summary

The present invention relates to methods for controlling hybridization in plants and producing hybrid plants. The present invention also relates to nucleic acids encoding amino acid sequences for self-incompatibility (SI) proteins in plants, and the use thereof for the manipulation of SI, including seed production, in plants, particularly of the Solanaceae family. The present invention also relates to kits, compositions, constructs and vectors including such nucleic acids, and related polypeptides, regulatory elements and methods as well as resultant plant varieties developed through the use of self-pollination.