2012
Enhancing Soybean Yield by Manipulating the Expression of Seed Size-Determining Genes (Year 2 of 1244)
Contributor/Checkoff:
Category:
Sustainable Production
Keywords:
(none assigned)
Lead Principal Investigator:
Aardra Kachroo, University of Kentucky
Co-Principal Investigators:
Project Code:
2244
Contributing Organization (Checkoff):
Institution Funded:
Brief Project Summary:

Unique Keywords:
#breeding & genetics, #seed size, fatty acid synthesis, fad3 genes, gmrin gene, cytokinins, bpmv gene silencing vector
Information And Results
Project Deliverables

Final Project Results

Update:
The project's objectives and KPIs were only partially addressed after several delays and a lengthy no-cost extension. The following were key results relative to the original objectives:
• Early results showed that silencing of the gene GmFAD3 increased seed size by 15% but subsequent tests did not. Silencing or over-expression of GmRIN did not affect seed size.
• Over-expression of GmFAD3 did not alter seed size or quality.
• Further determination the impact of silenced GmFAD3 plants indicated a slightly greater tolerance to stress induced by salt content, heat, or water deficit under greenhouse conditions. These are just one set of results performed only under lab conditions.
• Tests on CKOx (cytokinins) either silenced or over-expressed in plants did not alter seed size or quality.
• Silencing of DELLA genes did not affect seed size or quality.
• Other genes silenced were GmPAL and GmICS that did not alter seed size but showed an increase in phenyalanine which suggest that the slight increase in the amino acids tryptophan and tyrosine may have been due to an increase in phenylalanine.

Determination of seed size is a complex trait as proven here. No consistent positive results were shown after 5 years of lab experiments. It appears that no one plant gene, affecting either fatty acid or plant hormone or disease resistance as tested here, affects seed size.

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.