花生长链酰基辅酶A合成酶6基因(LACS6)的克隆、鉴定与组织表达

长链酰基辅酶A合成酶(long chain acyl-CoA synthetase:LACS)是油脂代谢的重要催化酶。为揭示花生脂肪酸代谢机理,采用RT-PCR技术,首次从花生Arachis hypogaea L.克隆到LACS6(GenBank登录号:KU301860),分析该基因的结构组成,预测编码氨基酸与其他植物的同源性,采用Real-Time PCR技术对LACS6的组织表达进行研究。结果显示,花生LACS6基因全长2 116bp,包含2 088bp的ORF,编码695个氨基酸,有23个外显子和22个内含子。氨基酸序列比对显示花生LACS6有真核生物酰基辅酶A合成酶保守结构域,并含有保守的激活位点和绑定位点。同源性分析发现花生LACS6与鹰嘴豆、绿豆、大豆、梅等13种物种的氨基酸一致性在79%~87%,进化树分析显示,花生LACS6与鹰嘴豆等豆科植物亲缘较近。实时荧光PCR分析表明,花生LACS6在花生根、茎、叶、子房柄、仁和花等组织均有表达,且差异明显。子房柄和花的表达量极高,与根、茎、叶和仁等组织有极显著差异,花生LACS6组织的表达量大小排序为花子房柄叶仁茎根。本研究结果为揭示花生脂肪酸代谢和品质改良提供理论依据。

Cloning,Verification and Tissue Expression of Long-chain Acyl-CoA Synthetase 6 (LACS 6) Gene in Peanut (Arachis hypogaea L.)

Long-chain acyl coenzyme A synthetase (LACS)is one of the important catalytic lipid metabolic enzymes in peanut plants.To understand the mechanism of the fatty acid metabolism in peanut (Arachis hypogaea L.),the cDNA of LACS 6 gene was cloned by RT-PCR (GenBank accession number:KU301860 ).Its structure was analyzed,homology with other plants compared,and mRNA expression in different tissues obtained using real-time PCR.The results showed that the cDNA was 2,1 1 6 bp including an open reading frame of 2,088 bp,encoded 695 amino acids,and had 23 exons and 22 introns.Its amino acid sequence alignment showed a conserved domain of eukaryotic long-chain fatty acid CoA synthetase,as well as conserved activation and binding sites.The homologies of LACS 6 gene with the genes from Cicer arietinum ,Vigna radiate ,Glycine max ,Prunus mume and others were between 79% and 87%.The evolutionary tree indicated that the gene was close to those from leguminous plants, such as chickpeas.The real-time PCR analysis showed that it was differentially expressed in the ovary stalks,roots, stems,leaves,flowers and kernels on a peanut plant.The ovary stalks and flowers had the highest expressionamong all,and with significant differences,The order of expression ranked as flowers > ovary stalks > leaves >kernels > stems > roots.The information obtained would benefit further studies on the fatty acid metabolism and quality improvement for peanut.