Shandong Peanut Research Institute, Qingdao, 266100, People's Republic of China.
Plant Cell Rep. 2011 Aug;30(8):1393-404. doi: 10.1007/s00299-011-1048-4. Epub 2011 Mar 16.
Fatty acid desaturases are responsible for the insertion of double bonds into pre-formed fatty acid chains in reactions that require oxygen and reducing equivalents. In this study, genes for FAB2, FAD2-2, FAD6 and SLD1, were cloned from peanut (Arachis hypogaea L.). The ORFs of the four genes were 1,221, 1,152, 1,329 and 1,347 bp in length, encoding 406, 383, 442 and 448 amino acids, respectively. The predicted amino acid sequences of AhFAB2, AhFAD2-2, AhFAD6, AhSLD1 shared high sequence identity of 79, 76.2, 73.4 and 61% to the corresponding ones in Arabidopsis, respectively. Heterologous expression in yeast was used to confirm the regioselectivity and the function of AhFAD2-2 and AhFAD6. Linoleic acid (18:2), normally not present in wild-type yeast cells, was detected in transformants of these two genes. Quantitative real-time RT-PCR analysis indicated that the transcript abundances of AhFAB2 and AhFAD2-1 were higher in seed than that in other tissues examined. On the other hand, transcript of AhFAD2-2, AhFAD6 and AhSLD1 showed higher abundances in leaves. In addition, these five genes showed different expression patterns during seed development. These results indicated that the five genes may have different biochemical functions during vegetative growth and seed development.
脂肪酸去饱和酶负责在需要氧气和还原当量的反应中将双键插入预先形成的脂肪酸链中。在这项研究中，从花生（Arachis hypogaea L.）中克隆了 FAB2、FAD2-2、FAD6 和 SLD1 的基因。这四个基因的 ORF 长度分别为 1,221、1,152、1,329 和 1,347 bp，分别编码 406、383、442 和 448 个氨基酸。AhFAB2、AhFAD2-2、AhFAD6 和 AhSLD1 的预测氨基酸序列与拟南芥相应序列的同源性分别高达 79%、76.2%、73.4%和 61%。在酵母中的异源表达用于确认 AhFAD2-2 和 AhFAD6 的区域选择性和功能。亚油酸（18:2），通常不存在于野生型酵母细胞中，在这两个基因的转化体中被检测到。定量实时 RT-PCR 分析表明，AhFAB2 和 AhFAD2-1 的转录丰度在种子中高于其他检测组织。另一方面，AhFAD2-2、AhFAD6 和 AhSLD1 的转录本在叶片中丰度较高。此外，这五个基因在种子发育过程中表现出不同的表达模式。这些结果表明，这五个基因在营养生长和种子发育过程中可能具有不同的生化功能。
