不同温度和N、Fe^(3+)质量浓度对微拟球藻脂肪酸组成及SCD基因表达的影响  

Effects of the Temperature,Nitrogen and Iron Stress on the Composition of Fatty Acids and the Transcription of SCD Gene in Nannochloropsis gaditana

作　　者：黄一江[1,2] 郑明刚[2] 孙中涛[1] 郑立[2] 王玲[3] 杨佰娟[2] 

机构地区：[1]山东农业大学生命科学学院,山东泰安271018 [2]国家海洋局第一海洋研究所,山东青岛266061 [3]青岛大学化学化工与环境学院,山东青岛266071

出　　处：《海洋科学进展》2014年第1期92-98,共7页Advances in Marine Science

基　　金：国家自然科学基金--海洋微拟球藻(Nannochloropsis sp.)油脂积累转录因子的研究(41106148);海洋可再生能源专项--海洋微藻制备生物柴油耦合CO2减排技术研究与示范(GHME2001SW02)

摘　　要：为了研究不同温度和N、Fe3+质量浓度对微拟球藻脂肪酸组成的影响,采用气相色谱-质谱联用仪,测定了不同处理条件下微拟球藻脂肪酸的组成。并利用荧光定量PCR技术,监测了在不同处理条件下微拟球藻硬脂酰辅酶A去饱和酶(SCD)基因的表达差异。结果表明:在缺N的条件下,微拟球藻中的不饱和脂肪酸的比例如C18∶2、C18∶1和C20∶4明显降低;在富N条件下C18∶2、C20∶4和C20∶5等不饱和脂肪酸的比例明显提高;在高温处理下,微拟球藻中C16∶1和C18∶1等单不饱和脂肪酸占总脂肪酸的比例有显著提高,而C20∶4和C20∶5等多不饱和脂肪酸则有明显的降低趋势;在低温处理组中,多不饱和脂肪酸如C18∶2和C20∶4在微拟球藻总脂中的比例明显提高;在富Fe条件下,多不饱和脂肪酸尤其是C20∶4和C20∶5发生积累;在缺Fe条件下,不饱和脂肪酸如C18∶1、C20∶5等占总脂肪酸的比例明显下降。与此同时,在富N、低温、高温和富Fe的条件下,SCD基因的表达量有显著的提高;在缺N和缺Fe的条件下,SCD基因的表达量下降。这揭示了SCD基因在不饱和脂肪酸形成途径中所起的重要作用,同时也证明了基因的表达与产物的合成有着密切的联系。In order to study the effect of different temperature, nitrogen and iron concentrations on the composition of fatty acids in Nannochloropsis gaditana, GC-MS and real-time PCR were used to analyze the composition of fatty acids and the transcription of stearoyl-coenzyme A desaturase （SCD） gene related to the synthesis of unsaturated fatty acid, under different treatments, respectively. Results showed that under nitrogen starvation and iron starvation, the proportions of unsaturated fatty acids such as 18 ： 2, 18 ： 1 and 20 ： 4 in total fatty acids were decreased. Under nitrogen excess, low temperature and iron ex-cess, the proportions of unsaturated fatty acids such as 18 ： 2, 20 ： 4 and 20 ： 5 were increased significant-ly. Whereas under high temperature, the proportions of monounsaturated fatty acids were increased. Meanwhile the transcription level of SCD gene was increased under nitrogen excess, low temperture, high temperture and iron excess, but it was decreased under nitrogen starvation and iron starvation. This study not only revealed that the SCD gene plays an important role in unsaturated fatty acid formation, but also proved that the SCD gene expression and the synthesis of related products have a positive correlation.

关 键 词：微拟球藻 不饱和脂肪酸 荧光定量PCR 硬脂酰辅酶A去饱和酶 

分 类 号：X834[环境科学与工程—环境工程]