油棕乙酰基酰基载体蛋白硫酯酶EgFATA基因的克隆与功能分析  

Cloning and functional analysis of the fatty acyl-ACP thioesterase EgFATA in oil palm

作　　者：金柳 李萌晗 郑育声[2] 李东栋[1,2] JIN Liu;LI Menghan;ZHENG Yusheng;LI Dongdong(School of Tropical Crops,Hainan University,Haikou,Hainan 570228;Sanya Nanfan Research Institute,Sanya,572024,China)

机构地区：[1]海南大学热带作物学院,海口570228 [2]海南大学三亚南繁研究院,三亚572024

出　　处：《热带生物学报》2023年第4期357-363,共7页Journal of Tropical Biology

基　　金：海南省重点研发项目(ZDYF2022XDNY148);海南省自然科学基金创新团队项目(2019CXTD397)。

摘　　要：为了探索油棕(Elaeis guineensis Jacq.)EgFATA基因的生物学功能,解析EgFATA基因在油棕中与脂肪酸积累的对应关系,为进一步研究EgFATA作用机制奠定基础,从油棕果cDNA中克隆得到了EgFATA基因的全长序列,经生物信息学分析发现,EgFATA编码区由1155个碱基组成,可编码385个氨基酸,相对分子量为91.89 kDa,与海藻PdFATA亲缘关系最近。在此基础上,构建EgFATA的病毒沉默载体并侵染油棕胚状体,RT-qPCR结果表明,EgFATA的表达量被下调85%~90%。同时,对基因沉默胚状体进行脂肪酸气相色谱法分析,硬脂酸(C18:0)、油酸(C18:1)、亚油酸(C18:2)的含量均显著性降低。以上结果表明在油棕胚状体中,EgFATA对C18:0-ACP、C18:1-ACP、C18:2-ACP的水解具有催化作用,且对C18:1-ACP的催化活性最强。Oil palm(Elaeis guineensis Jacq.)is an important tropical palm with high oil production.Fatty acyl-ACP thioesterase(FAT)is the key enzyme for hydrolysis of acyl and ACP and termination of carbon chain extension.The oil palm FATA family mainly acts on eighteen-carbon chain fatty acids(18:X-ACP),but the specific hydrolysis substrates and preferences are unknown.In this study,the full-length sequence of the EgFATA gene was first cloned from oil palm fruit.Bioinformatics analysis indicated that the EgFATA coding region consists of 1155 bases and can encode 385 amino acids with a molecular weight of 91.89 kDa,and is most closely related to the alga PdFATA.A viral silencing vector for EgFATA was constructed and then infected the embryoids of oil palm,and RT-qPCR results showed that the expression of EgFATA was down regulated by 85%-90%.At the same time,fatty acid GC analysis of the silenced embryoids showed that the contents of stearic acid(C18:0),oleic acid(C18:1)and linoleic acid(C18:2)were significantly reduced.The aforesaid results indicated that EgFATA had catalytic effect on the hydrolysis of C18:0-ACP,C18:1-ACP and C18:2-ACP in the oil palm embryoids,with the highest catalytic activity observed in the hydrolysis of C18:1-ACP.This study initially explored the biological functions of EgFATA genes in oil palm,providing a theoretical basis for further exploration of the molecular mechanisms of EgFATA in regulation of lipid metabolism.

关 键 词：油棕 乙酰基酰基载体蛋白硫酯酶 油脂代谢调控 

分 类 号：Q786[生物学—分子生物学]