Shanxi Agricultural University, Taigu 030801, China.
Funct Integr Genomics. 2013 Mar;13(1):99-113. doi: 10.1007/s10142-012-0306-z. Epub 2013 Jan 16.
Diacylglycerol acyltransferase (DGAT) catalyzes the acyl-CoA-dependent acylation of sn-1,2-diacylglycerol to form seed oil triacylglycerol (TAG). To understand the features of genes encoding soybean (Glycine max) DGATs and possible roles in soybean seed oil synthesis and accumulation, two full-length cDNAs encoding type 1 diacylglycerol acyltransferases (GmDGAT1A and GmDGAT1B) were cloned from developing soybean seeds. These coding sequences share identities of 94 % and 95 % in protein and DNA sequences. The genomic architectures of GmDGAT1A and GmDGAT1B both contain 15 introns and 16 exons. Differences in the lengths of the first exon and most of the introns were found between GmDGAT1A and GmDGAT1B genomic sequences. Furthermore, detailed in silico analysis revealed a third predicted DGAT1, GmDGAT1C. GmDGAT1A and GmDGAT1B were found to have similar activity levels and substrate specificities. Oleoyl-CoA and sn-1,2-diacylglycerol were preferred substrates over vernoloyl-CoA and sn-1,2-divernoloylglycerol. Both transcripts are much more abundant in developing seeds than in other tissues including leaves, stem, roots, and flowers. Both soybean DGAT1A and DGAT1B are highly expressed at developing seed stages of maximal TAG accumulation with DGAT1B showing highest expression at somewhat later stages than DGAT1A. DGAT1A and DGAT1B show expression profiles consistent with important roles in soybean seed oil biosynthesis and accumulation.
二酰基甘油酰基转移酶（DGAT）催化酰基辅酶 A 依赖性 sn-1,2-二酰基甘油的酰化，形成种子油三酰基甘油（TAG）。为了了解编码大豆（Glycine max）DGAT 的基因的特征及其在大豆种子油合成和积累中的可能作用，从发育中的大豆种子中克隆了两个编码 1 型二酰基甘油酰基转移酶（GmDGAT1A 和 GmDGAT1B）的全长 cDNA。这些编码序列在蛋白质和 DNA 序列上的同源性分别为 94%和 95%。GmDGAT1A 和 GmDGAT1B 的基因组结构都包含 15 个内含子和 16 个外显子。在 GmDGAT1A 和 GmDGAT1B 的基因组序列之间发现了第一个外显子和大多数内含子的长度差异。此外，详细的计算机分析还揭示了第三个预测的 DGAT1，GmDGAT1C。发现 GmDGAT1A 和 GmDGAT1B 具有相似的活性水平和底物特异性。油酰基辅酶 A 和 sn-1,2-二酰基甘油是优于 vernoloyl-CoA 和 sn-1,2-二异戊酰基甘油的底物。这两种转录物在发育中的种子中的丰度都远高于其他组织，包括叶片、茎、根和花。在最大 TAG 积累的发育种子阶段，大豆 DGAT1A 和 DGAT1B 的表达量都很高，DGAT1B 的表达量略高于 DGAT1A。DGAT1A 和 DGAT1B 的表达谱与它们在大豆种子油生物合成和积累中的重要作用一致。
