Laboratory of Plant Genetics and Breeding, Faculty of Agriculture, Saga University , Honjyo-machi 1, Saga 840-8502, Japan.
Breed Sci. 2012 Jan;61(5):631-8. doi: 10.1270/jsbbs.61.631. Epub 2012 Feb 4.
Palmitic acid is the most abundant (approx. 11% of total fatty acids) saturated fatty acid in conventional soybean seed oil. Increasing the saturated acid content of soybean oil improves its oxidative stability and plasticity. We have developed three soybean mutants with high palmitic acid content by X-ray irradiation. In this study, we successfully identified the mutated sites of two of these high-palmitic-acid mutants, J10 and M22. PCR-based mutant analysis revealed that J10 has a 206,203-bp-long deletion that includes the GmKASIIA gene and 16 other predicted genes, and M22 has a 26-bp-long deletion in the sixth intron of GmKASIIB. The small deletion in M22 causes mis-splicing of GmKASIIB transcripts, which should result in nonfunctional products. In addition, we designed co-dominant marker sets for these mutant alleles and confirmed the association of genotypes and palmitic acid contents in F(2) seeds of J10 X M22. This information will be useful in breeding programs to develop novel soybean cultivars with improved palmitic acid content. However, in the third mutant, KK7, we found no polymorphism in either GmKASIIA or GmKASIIB, which suggests that several unknown genes in addition to GmKASIIA and GmKASIIB may be involved in elevating the palmitic acid content of soybean seed oil.
棕榈酸是传统大豆籽油中含量最丰富的（约占总脂肪酸的 11%）饱和脂肪酸。增加大豆油中的饱和酸含量可以提高其氧化稳定性和塑性。我们通过 X 射线辐射开发了三种高棕榈酸含量的大豆突变体。在这项研究中，我们成功地鉴定了其中两个高棕榈酸突变体 J10 和 M22 的突变位点。基于 PCR 的突变分析表明，J10 有一个 206,203-bp 长的缺失，其中包括 GmKASIIA 基因和 16 个其他预测基因，而 M22 在 GmKASIIB 的第六个内含子中有一个 26-bp 长的缺失。M22 中的小缺失导致 GmKASIIB 转录物的错误剪接，这应该导致无功能产物。此外，我们为这些突变等位基因设计了共显性标记集，并在 J10 X M22 的 F2 种子中证实了基因型和棕榈酸含量的关联。这些信息将有助于开发新型高棕榈酸含量的大豆品种的选育计划。然而，在第三个突变体 KK7 中，我们在 GmKASIIA 或 GmKASIIB 中都没有发现多态性，这表明除了 GmKASIIA 和 GmKASIIB 之外，可能还有几个未知基因参与了大豆籽油中棕榈酸含量的升高。
