A New Strategy for Elevating Soybean Yield: Manipulating Nodulation and Nitrogen Fixation Efficiencies through Gene Editing (Year 3)
Sustainable Production
AgricultureGeneticsNitrogen fixation
Parent Project:
This is the first year of this project.
Lead Principal Investigator:
Jianxin Ma, Purdue University
Co-Principal Investigators:
Project Code:
Contributing Organization (Checkoff):
Institution Funded:
Brief Project Summary:
In FY21, we initiated a three-year project that aimed to explore and develop an innovation strategy to substantially boost soybean yield. Specific objectives include: 1) characterization of novel soybean genes associated with nodulation efficiency; 2) creation of soybean lines with increased efficiencies for nodule formation and/or SNF using the genome-editing technology; and 3) evaluation and identification of soybean lines with edited genes for enhanced grain yield and possibly increased protein content as well. We have made exciting processes on Objectives 1 and 2 and expect to achieve Objective 3 through the part of FY22 and the whole FY23 period. Our strategy can be extended to elite cultivars for enhanced plant productivity and grain yield without a need of adding fertilizer nitrogen, and also for increased soil nitrogen levels for the next crop in rotation. Thus, the successful implementation of our strategy would make the U.S. soy. production more economical and sustainable, the US soy more competitive in the global market.
Information And Results
Project Summary

Project Objectives

Project Deliverables

Progress Of Work

Final Project Results

Soybean seeds are enriched with proteins, as such the crop has a high demand for nitrogen. Instead of relying solely on nitrogen in the soil, soybean can produce root nodules, within which rhizobia can converts atmospheric nitrogen into a form the host plant can use – a natural process called symbiotic nitrogen fixation (SNF). It is estimated that 50-60% of the nitrogen needed for soybean production is provided by SNF; nevertheless, the crop’s need for additional nitrogen remains substantial. People tend to speculate that such an addition can be supplied by nitrogen fertilizer, but adding fertilizer, in most cases, does not result in yield increases, because the fertilizer nitrogen inhibits the activities of rhizobia. Therefore, applying fertilizer nitrogen to soybean fields is not an economical and effective way to boost yield. In FY21, we initiated a three-year project that aimed to optimize the plant’s natural process to fix more atmospheric nitrogen for enhanced yield potential and reduced use of nitrogen fertilizer. Towards this goal, we proposed three specific objectives: 1) identify and characterize 4-6 soybean genes primarily repressing nodulation; 2) create soybean overexpression/knockout (i.e., an experimental line in which a specific gene loses its function) lines with increased nodulation and/or nitrogen-fixation efficiency though the CRISPR-Cas9 (a technique enable to make a gene lose its function) based editing of these genes; 3) evaluate and identify soybean overexpression/knockout lines for enhanced productivity and grain yield. In this FY23 period, we focused primarily on Objective 3 and have achieve all as proposed. We obtained 6 stable gene-editing/overexpression lines, some of which showed enhanced symbiotic nitrogen-fixation efficiency, plant productivity, yield component traits, and altered seed composition. Field tests for additional years/environments are needed in order to translate the findings into elite soybean varieties.

Benefit To Soybean Farmers

This project explores a new strategy for enhancing soybean productivity and grain yield by enhancing the plant's capability to utilize the atmospheric nitrogen through synbiotic nitrogen fixation. This strategy can be extended into enhancement of elite soybean lines to make the US soybean production more economical and sustainable and the US soy more competitive in the global market.

The United Soybean Research Retention policy will display final reports with the project once completed but working files will be purged after three years. And financial information after seven years. All pertinent information is in the final report or if you want more information, please contact the project lead at your state soybean organization or principal investigator listed on the project.