【摘要】 微藻燃油是绿色可再生的替代性能源。解析微藻油脂合成调控机制是提高微藻油脂产量和微藻燃油规模化生产必须回答的重要议题。本研究以单细胞光自养模式植物莱茵衣藻(Chlamydomonas reinhardtii)为试材,以参与三酰甘油(triacylglycerol,TAG)最后一步酰化反应的二酰基甘油转移酶(diacylglycerol acy ltransf-erase,DGAT)为靶标,采用生物信息学等分析手段,全基因组鉴定Ⅱ-型DGAT(DGAT2)基因家族成员及其表达模式。研究结果表明,莱茵衣藻Cre DGAT2家族有5个成员,命名为Cre DGTT1-5。Cre DGAT2基因含有5~12个内含子和6~13个外显子。Cre DGAT2可分为三个亚族,即Cre DGTT1和Cre DGTT4各自为一亚族,Cre DGTT2、Cre DGTT3和Cre DGTT5组成另一亚族,各亚族分别具有独特的理化特性。缺氮胁迫诱导Cre DGTT1高表达,而盐胁迫导致Cre DGTT4上调表达。预示着不同的Cre DGT2成员参与不同胁迫条件下微藻油脂合成的应答反应。本研究获得的有关莱茵衣藻DGAT2基因家族蛋白理化性质、蛋白结构、基因结构以及系统进化等信息为进一步全面解析微藻DGAT2基因的生物学功能以及鉴定油脂代谢工程靶标分子提供了科学参考。更多还原

【Abstract】 Algae biofuel is a green and renewable alternative energy sources. It is one of the important issues to understand the oil biosysnthesis and its regulatory mechanism in microalgae for improving microalgae oil yield and biofuel production on a large scale. Here, Chlamydomonas reinhardtii, the single-cell photoautotrophic model plant, was used for such study by focusing diacylglycerol acyltransferase(DGAT) which catalyzes the final step of triacylglycerol(TAG) biosynthesis. Bioinformatics analysis and other tools were employed for genome-wide identification of Ⅱ-type DGAT(DGAT2) gene family members and their expression patterns under stresses. The results showed that C. reinhardtii Cre DGAT2 family has five members, namely Cre DGTT1-5. Cre DGAT2 gene contains5~12 introns and 6~13 exons. Cre DGAT2 family was classed into three subfamilies. Cre DGTT1 and Cre DGTT4 were grouped to two different subfamilies while Cre DGTT2, Cre DGTT3 and Cre DGTT5 formed another subfamily. Each subfamily has a unique physical and chemical property, respectively. Nitrogen deficiency induced high expression of Cre DGTT1, whereas salt stress upregulated Cre DGTT4 expression, indicating that different members of Cre DGTT2 participate in responses of lipid synthesis to different stresses. The present data of Molecular Plant Breeding Cre DGAT2 including protein physicochemical properties and structure, gene structure and system evolution provide a scientific reference for comprehensive analysis of Cre DGAT2 gene biological functions and identification of the target molecule in oil metabolic engineering.更多还原