2014
Modifying Bradyrhizobium japonicum to enhance nodulation soybean disease resistance
Contributor/Checkoff:
Category:
Sustainable Production
Keywords:
GeneticsGenomicsSeed quality
Parent Project:
This is the first year of this project.
Lead Principal Investigator:
Reuben Peters, Iowa State University
Co-Principal Investigators:
Leonor Leandro, Iowa State University
Alison Robertson, Iowa State University
Gregory Tylka, Iowa State University
+2 More
Project Code:
Contributing Organization (Checkoff):
Institution Funded:
Brief Project Summary:

The goal of this proposal is to develop a modified strain of BBradyrhizobium japonicum that continues to provide all the nitrogen-fixing benefits of nodulation and does not suppress soybean plant defense against other microbes (i.e. disease-causing pathogens) and potentially the soybean cyst nematode as well. Development of such a strain would enhance the disease resistance of nodulated soybeans, hence, providing obvious benefits for the farmers.

Unique Keywords:
#bradyrhizobium inoculants, #nitrogen fixation, #soil fertility
Information And Results
Project Deliverables

Final Project Results

In the past year, we discovered that B. japonicum makes GA most strongly during the flowering stage of soybean. Given that our previous studies were largely focused on earlier stages, we have verified that the ga-­- knock-­-out strain is still able to fix nitrogen and enable soybean plant growth in an equivalent manner to the parental GA+ B. japonicum through the flowering stage. In addition, we have carried out experiments for each of the three project objectives outlined above, using plants both just before and in the flowering stage. Our data for SDS indicates that soybean plants nodulated with the ga-­- knock-­-out strain are significantly more resistant to SDS than those nodulated with the parental GA+ B. japonicum if infected before, but not during, the flowering stage. We are currently repeating these experiments to verify and further investigate the effect of plant developmental stage.
Nevertheless, given that the tested diseases target seedlings, we remain optimistic that this approach may be of agricultural utility.

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.