Soybean GmNNL1 R Gene for Selective Rhizobium Nodulation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The nodulation ability of indigenous rhizobia in soybean fields is weaker than that of high-efficiency rhizobia agents, limiting the effectiveness of inoculation and reducing symbiotic nitrogen fixation, with existing methods failing to effectively regulate soybean-rhizobium compatibility.

Innovation Solution

The introduction of an R gene, specifically GmNNL1, which can regulate soybean-rhizobium symbiotic compatibility by limiting indigenous rhizobia nodulation and enhancing compatibility with high-efficiency rhizobia agents, achieved through genome-wide association analysis and CRISPR-Cas9 modification, along with Agrobacterium-mediated transformation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If indigenous rhizobia are used for nodulation, then soybean can establish symbiotic relationships, but the nodulation ability is weak and limits the effectiveness of high-efficiency rhizobia agents

Engineering Contradiction:

Improvesymbiotic nitrogen fixationVSAvoidnodulation ability

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The R gene GmNNL1 is designed to recognize and restrict indigenous rhizobia carrying the NopP effector protein before they can establish effective nodulation. This preliminary restriction prevents indigenous rhizobia from competing with high-efficiency inoculated strains, thereby improving the overall productivity of symbiotic nitrogen fixation without compromising the reliability of the symbiotic relationship

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

The invention changes the compatibility parameter between soybean and rhizobia by introducing the R gene GmNNL1 with specific haplotypes that alter the recognition pattern. This parameter change enables the soybean to distinguish between indigenous rhizobia (restricted) and high-efficiency inoculated rhizobia (permitted), thereby resolving the contradiction between maintaining symbiotic reliability and improving nodulation productivity

Inventive Principle:

Principle #35Parameter changes

2Productivity

If high-efficiency rhizobia agents are inoculated, then nitrogen fixation efficiency improves, but indigenous rhizobia with strong adaptability limit their effectiveness

Engineering Contradiction:

Improvesymbiotic nitrogen fixationVSAvoidindigenous rhizobia adaptability

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

The R gene GmNNL1 acts as an intermediary mechanism that mediates the interaction between soybean and different rhizobia types. It specifically targets the NopP effector protein from indigenous rhizobia as a mediator of restriction, while allowing high-efficiency inoculated strains (that lack or have different effector profiles) to establish nodulation successfully. This intermediary mechanism resolves the conflict between productivity improvement and indigenous adaptability

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention applies local quality by creating site-specific recognition and restriction. The R gene GmNNL1 with specific haplotypes (HT1, HT3, HT5) provides localized resistance against indigenous rhizobia carrying NopP, while leaving other rhizobia types and high-efficiency inoculated strains unaffected. This localized action allows high-efficiency nodulation without being limited by widespread indigenous adaptability

Inventive Principle:

Principle #3Local quality

3Adaptability or versatility

If R gene GmNNL1 is introduced to restrict indigenous rhizobia, then compatibility with high-efficiency rhizobia improves, but genetic modification complexity increases

Engineering Contradiction:

Improvesoybean-rhizobia compatibilityVSAvoidgenetic modification

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The invention utilizes natural genetic variation by identifying and utilizing existing R gene haplotypes (HT1, HT3, HT5) that occur in soybean populations. Rather than creating entirely new genetic constructs, the approach copies and propagates naturally occurring functional haplotypes that provide the desired compatibility improvement. This copying strategy reduces genetic modification complexity compared to de novo gene synthesis

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The R gene GmNNL1 with specific haplotypes provides multi-functional benefits: it restricts indigenous rhizobia, permits high-efficiency inoculated strains, and can be applied across different soybean varieties. This universal applicability reduces the need for variety-specific modifications, thereby reducing overall genetic modification complexity while improving broad compatibility

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS12522840B2R gene for controlling matching of soybean-rhizobium, protein and use thereof

Publication Date: 2026.01.13 HENAN UNIVERSITY

AI summary

A R gene is arranged for controlling soybean-rhizobia compatibility, wherein the GmNNL1 gene of the gene sequence in Hengfeng black bean of the soybean products is shown in SEQ ID NO. 2, and the encoded amino acid sequence is shown in SEQ ID NO. 3. The soybean R gene GmNNL1 is an effective gene that is able to regulate the nodule number of specific rhizobia on soybean, and to regulate the nodule number by directly recognizing the haplotype of the bradyrhizobia-specific effector protein NopP, which is able to limit the symbiotic nodulation of indigenous rhizobia, make soybean preferentially nodule with artificially applied high-efficiency rhizobia agents, and improve symbiotic nitrogen fixation capacity.