不同外源诱导子对三角褐指藻lcyb基因转录及其岩藻黄素含量的影响

发布时间：2019-06-02 13:10

【摘要】：番茄红素β-环化酶(lycopene beta-cyclase,LCYB)能催化番茄红素形成β-胡萝卜素及其氧化物,是处于植物类胡萝卜素合成途径中的一个分支点。为研究三角褐指藻(Phaeodactylum tricornutum)在不同外源诱导下lcyb基因的表达情况及其对岩藻黄素积累的影响,本研究通过从头测序(de novo测序)获得三角褐指藻lcyb基因c DNA全长并对其进行生物信息学分析,进一步对经过不同浓度的茉莉酸甲酯(methyl jasmonate,Me JA)、乙酰水杨酸(acetylsalicylic acid,ASA)、花生四烯酸(arachidonic acid,AA)和硫酸铈铵(ammonium cerous sulfate,ACS)处理的三角褐指藻lcyb基因表达进行分析,并对其岩藻黄素含量进行测定。结果表明,本研究通过转录组获得的三角褐指藻lcyb基因序列与NCBI上已知序列(Gen Bank No.XM002176576)相同,其c DNA全长为2 060 bp,含1个长度为1 980 bp的开放阅读框(open reading fragment,ORF),编码659个氨基酸,该蛋白在N端含有1个双核苷酸结合位点,在C端含有1个螺旋跨膜区域,存在叶绿体导肽和信号肽,定位于叶绿体类囊膜上。系统发育进化树显示,三角褐指藻等硅藻共处1个进化支,亲缘关系较近。诱导转录结果表明,50μmol/L Me JA、10 mg/L ASA、0.1 mg/L AA和0.4 mg/L ACS处理后的三角褐指藻lcyb基因在本实验范围内转录表达水平最高,且三角褐指藻中的岩藻黄素含量随着lcyb基因转录量的增加而增加,并呈正相关,说明该酶在岩藻黄素合成过程中起到重要作用,诱导子能增强该基因转录从而达到提高岩藻黄素含量的目的。本研究为岩藻黄素的合成调控提供理论指导,也为进一步通过代谢工程手段提高三角褐指藻中的岩藻黄素含量提供参考。
[Abstract]:Lycopene 尾-cyclase (lycopene beta-cyclase,LCYB) can catalyze lycopene to form 尾-carotene and its oxides, which is a branch of plant carotenoid synthesis pathway. In order to study the expression of lcyb gene in Phaeodactylus triangularis (Phaeodactylum tricornutum) induced by different exogenous sources and its effect on the accumulation of alginin, In this study, the full length of lcyb gene c DNA was obtained by ab initio sequencing (de novo sequencing, and its bioinformatics analysis was carried out. Methyl jasmonate,Me JA), acetylsalicylic acid (acetylsalicylic acid, with different concentrations was further studied. The lcyb gene expression of ASA), arachidonic acid (arachidonic acid,AA) and ammonium cerium sulfate (ammonium cerous sulfate,ACS) was analyzed and the content of alginin was determined. The results showed that the lcyb gene sequence of Phaeodactylus triangularis obtained from the transcriptional group was the same as that of the known sequence (Gen Bank No.XM002176576 on NCBI. The c DNA was 2060 bp, with an open reading frame (open reading fragment,ORF of 1.980 bp in length. It encodes 659 amino acids. The protein contains a dinucleotides binding site at the N-terminal and a spiral transmembrane region at the C-terminal. Chloroplast conduction peptides and signal peptides are located on the chloroplast capsule. The phylogenetic tree showed that diatoms such as Phaeodactylus triangularis coexisted with one evolutionary branch and were closely related to each other. The results of induced transcription showed that the lcyb gene of Phaeodactylus triangularis treated with 50 渭 mol / L Me JA,10 mg/L ASA,0.1 mg/L AA and 0.4 mg/L ACS had the highest transcriptional expression level in this experiment. The content of alginin in Phaeodactylus triangularis increased with the increase of lcyb gene transcription, and there was a positive correlation, which indicated that the enzyme played an important role in the synthesis of alginin. The inducer can enhance the transcription of the gene and increase the content of alginin. This study provides theoretical guidance for the synthesis and regulation of alginin, and also provides a reference for further improving the content of alginin in Phaeodactylus triangularis by means of metabolic engineering.
【作者单位】：宁波大学海洋学院;
【基金】：国家星火计划项目(No.2015GA701001) 浙江省科技厅重点科技创新团队项目(No.2012R10029-07和No.2010R50029) 宁波科技攻关项目(No.2013C10018和No.2014C91023)
【分类号】：Q943.2

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