Studies about the improvement of soybean storage lipids by using the combination of induced mutation and gene transfer techniques.

在本研究中，我们试图培育一种既具有修饰脂肪酸组成又具有高产油性的大豆种质，并利用该组合获得了以下结果1。在几个高油酸突变体中发现了相应的基因，其中两个突变体(KK21和M23)被证实发生在编码微粒体ω-6脂肪酸去饱和酶的GmFAD2-I基因座上。此外，J18和M5的低亚麻酸突变体存在GmFAD3-1a突变，M24的相应基因也明确了该突变发生在编码微粒体ω-3脂肪酸去饱和酶基因的另一个GmFAD3-1b基因座上。结果表明，添加20 mM焦谷氨酸可显著提高大豆幼胚的胚胎发生效率，添加0.2%S多糖对大豆幼胚的生长也有一定的促进作用。在此条件下，通过导入绿色荧光蛋白基因，获得了日本品种九州126的三个转基因大豆品系。我们成功地培育出转GmFAD3-1a基因水稻，使种子的α-亚麻酸含量提高了10倍以上，并开发了一种新型的植物转化载体，证明了这些技术对于利用转基因技术改良大豆脂肪是有效的。它成功地克隆了编码二酰甘油酰基转移酶(DGAT)的基因(cDNA和基因组DNA)，该基因控制着猪油的组成(TAG/DAG比)和产油量。

In this study, we have attempted to develop a novel soybean germplasm which equips with both modified fatty acid composition and high oil productivity, and have obtained following results by using the combination1. The corresponding genes were identified in several high oleic acid mutants, and two of them (KK21 and M23) were clarified that mutations occurred at GmFAD2-I locus which encodes a microsomal ω-6 fatty acid desaturase. In addition, J18 and M5 of low linolenic acid mutants have mutations in GmFAD3-1a, and the corresponding gene of M24 is also clarified that the mutation occurs at another GmFAD3-1b locus, which encode microsomal ω-3 fatty acid desaturase genes.2. We found that the addition of 20mM pyroglutamic acid to culture meda drastically improved the embryogenesis efficiency from soybean immature embryo and the addition of 0.2% polypeptone S was also effective for the embryo growth. Furthermore, we have developed three transgenic soybean lines of Japanese cultivar, Kyushu 126, by introducing EGFP gene under those conditions.3. We have successfully developed the transgenic rice with GmFAD3-1a gene which have improved the α- linolenic acid content of seeds over 10-fold higher than that of non-transgenic rice, have developed a novel RNAi vector for plant transformation, and it was clarified that these techniques were effective for the improvement of the soybean lipid using the transgenic technology.4. It has successfully cloned the genes (cDNA and genomic DNA) encoding diacylglycerol acyl transferase (DGAT) which could control the lipig composition (TAG/DAG ratio) and oil yield.