油棕^(Δ)9硬脂酰-ACP脱氢酶基因(SAD)鉴定及表达分析

Identification and Expression Analysis of SAD Gene in Oil Palm

9硬脂酰-ACP脱氢酶(SAD)是调控油棕果实不饱和脂肪酸合成和积累的关键酶,鉴定油棕EgSAD家族成员,对其理化性质及表达模式的分析对EgSAD的基因功能及调控机制研究提供信息。本研究在全基因组范围内鉴定获得4个EgSAD基因,EgSAD1定位在油棕2号染色体上,EgSAD2定位在7号染色体上,Eg SAD4定位在11号染色体上,Eg SAD1有2个外显子,EgSAD2~EgSAD4有3个外显子。4个油棕EgSAD蛋白均定位在细胞核,油棕EgSAD1~EgSAD4蛋白质大小分别为471、393、391和399 aa,EgSAD1和Eg SAD2的等电点分别为6.05、EgSAD3和EgSAD4的等电点分别为5.99和7.13,分子量分别为43.41、45.01、44.94和45.92 kD。EgSAD2在油棕中果皮的4个时间点均超高量表达,其余3个基因在各组织中只有微量表达或不表达,该结果为油棕Eg SAD基因调控不饱和脂肪酸合成的分子机理解析理论依据。

^(Δ)9 stearoyl-ACP dehydrogenase(SAD)is the key enzyme that regulates the synthesis and accumulation of unsaturated fatty acids in oil palm fruit.Identification of the members of the EgSAD family of oil palm provides information for the study of the gene function and regulation mechanism of EgSAD by analyzing its physicochemical properties and expression patterns.In this study,four EgSAD genes were identified in the whole genome.EgSAD1 was located on chromosome 2 of oil palm,EgSAD2 was located on chromosome 7,EgSAD4 was located on chromosome 11,EgSAD1 had two exons,and EgSAD2~EgSAD4 had three exons.The four oil palm EgSAD proteins are located in the nucleus.The size of the oil palm EgSAD1~EgSAD4 proteins is 471,393,391 and 399 aa,respectively.The isoelectric points of EgSAD1 and EgSAD2 are 6.05,the isoelectric points of EgSAD3 and EgSAD4 are 5.99 and 7.13,and the molecular weights are 43.41,45.01,44.94 and 45.92 kD,respectively.EgSAD2 is highly expressed at four time points in the peel of oil palm,and the other three genes are only slightly expressed or not expressed in each tissue.This result lays a foundation for the molecular mechanism analysis of oil palm EgSAD gene regulating the synthesis of unsaturated fatty acids.