【摘要】 中国黄连木(Pistacia chinensis Bunge)是种重要的优良木本油料树种,分布广,而且种子具有含油量高、出油率高、油品质好等优点,是生产生物柴油的理想原料。硬脂酰-酰基载体蛋白脱饱和酶(stearoyl-ACP desat-urase,SAD)在植物中催化不饱和脂肪酸生物合成的第一步脱饱和反应,对植物细胞膜和种子油脂中脂肪酸成分的调控起着重要作用。本研究采用RACE及RT-PCR方法,首次从黄连木种子中克隆获得长度为1791bp的SAD基因(命名为PcSAD),该基因含有1299bp完整的开放阅读框、编码432个氨基酸。生物信息学分析发现,黄连木PcSAD基因的核苷酸序列及其编码的氨基酸序列与已报道的其它相近物种具有较高同源性,而且PcSAD含有典型的酰基载体蛋白脱饱和酶2和类铁蛋白家族的保守结构域;另外,开展了PcSAD的原核表达载体构建及诱导表达体研究。上述研究结果可为黄连木PcSAD基因的功能鉴及应用定奠定重要基础。更多还原

【Abstract】 Pistacia chinensis Bunge is one of the most important and superior oil woody tree species, widely distributed in China, with a higher oil content and oil-producing rate, and good oil quality in the seeds as an important resource for making biodiesel. It has been reported that stearoyl-acyl carrier protein desaturase （Stearoyl-ACP desaturase, SAD）, catalyzing the initial desaturation in the biosynthesis of unsaturated fatty acids in plants, play a key role in the regulation of fatty acid composition of plant membranes and seed oils. In this paper, a full-length cDNA with a size of 1 791 bp, designated as SAD gene （PcSAD）, was isolated from total RNA of the seeds of P. chinensis by RT-PCR and RACE techniques, and this cDNA contains an open-reading frame of 1 299 bp in length, encoding a polypeptide of 432 amino acid residues. The results of bioinformatics analysis showed that the cDNA of PcSAD gene and its encoded amino acid sequences exhibits a considerable degree of homology to those of the reported plants, and the protein thought to be produced by the PcSAD gene contains the classical conserved functional domains of Acyl-ACP desaturase₂ and ferritin-like superfamily. Additionally, the prokaryotic expression vector was constructed and the PcSAD expression in E. coli BL21 （DE3） was studied. The results mentioned above would provide the important basis for the functional identification and application of PcSAD gene in the future.更多还原