Submitted to: Plant Breeding
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/12/2006
Publication Date: 9/12/2006
Citation: Chappell, A.S., Bilyeu, K.D. 2006. A gmfad3a mutation in the low linolenic acid soybean mutant c1640. Plant Breeding. 125(5):535-536. Interpretive Summary: Commercial soybeans contain a relatively high level of linolenic acid, which is responsible for the poor flavor and odor stability of soybean oil. Thus, reducing linolenic acid in soybeans has become a primary objective in crop science research. To this end, low linolenic acid mutants have previously been developed through mutagenesis. In the work described here, a candidate mutated gene from C1640 was characterized and found to contain a deleterious change when compared to the gene from lines with normal linolenic acid contents. We have developed an assay to distinguish between the wild-type and mutant version of the gene. This assay will aid breeders that are trying to incorporate the low linolenic acid trait into other lines to improve the functionality of the oil made from new varieties.
Technical Abstract: The linolenic acid component is responsible for the flavor and odor instability of soybean oil. Thus, development of low linolenic acid soybean lines has been a major goal in crop science research. One such low linolenic acid soybean line, A5, contains a deletion of the omega-3 fatty acid desaturase gene GmFAD3A. Another low linolenic acid soybean line, C1640, is allelic with A5, suggesting it too contains a mutation in the GmFAD3A gene. The purpose of this work was to characterize the genetic lesion in C1640 using GmFAD3A as a candidate gene. We found that a premature stop codon is introduced in the gene, presumably rendering a non-functional truncated enzyme. We have developed an assay to distinguish between the wild type and mutant alleles by using PCR followed by endonuclease digestion. This assay will aid soybean breeders that are trying to incorporate the C1640 low linolenic acid trait into other lines.