Abstract
Oleic acid is one of the three major unsaturated fatty acids in soybean oil. Expression of the embryo-specific Fad2-1 gene correlates with fatty acid biosynthesis and oil deposition in developing seeds. Elevated levels of oleate in the X-ray-induced mutant line M23 have been shown to be associated with the deletion of a Fad2-1 gene. In soybean, two homologs of the Fad2-1 gene, termed Fad2-1a (L43920) and Fad2-1b (AY611472), presumably encode functional embryo-specific fatty acid desaturase. The objectives of this investigation were to determine which copy of the Fad2-1 gene is associated with the increased oleate content in the mutant line and what is the relative transcript abundance of these two embryo-specific genes. PCR and DNA blot analyses showed that increased oleate content in M23 mutant was associated with the deletion of Fad2-1a. These results were further validated using five independent soybean populations developed by crossing mid-oleate and normal-oleate parents. Investigation of the soybean expressed sequence tag database and reverse transcription PCR analyses revealed that Fad2-1b is the predominantly transcribed copy of the Fad2-1 gene. We hypothesize that null mutation in Fad2-1b in the fad2-1a mutant background should further elevate the oleic contents of soybean oil.
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We are grateful to Iowa Soybean Association for financial support.
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11746_2007_1037_MOESM1_ESM.doc
Supplemental Table 1. Differential expression levels of the Fad2-1a and Fad2-1b genes in developing soybean embryos. (DOC 28 kb)
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Sandhu, D., Alt, J.L., Scherder, C.W. et al. Enhanced Oleic Acid Content in the Soybean Mutant M23 Is Associated with the Deletion in the Fad2-1a Gene Encoding a Fatty Acid Desaturase. J Amer Oil Chem Soc 84, 229–235 (2007). https://doi.org/10.1007/s11746-007-1037-5
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DOI: https://doi.org/10.1007/s11746-007-1037-5