Carotenoid isomerase ( CRTISO) is a key enzyme in the pathway of carotenoid , which can catalyze the structure of carote-noids from cis-to trans-.Full length of crtiso in Dunadiella viridis was acquired by RNA-sequencing , then, the sequence was analyzed by several bioinformatics softwares .Transcriptional levels of D.viridis treated by different concentration of acetylsalicylic acid (ASA) and arachidonic acid (AA) were checked by real-time quantitative PCR.The full cDNA length of crtiso was 1176 bp.It contained a 795 bp open reading frame ( ORF) , encoding 264 amino acids .Relative molecular mass was 29 522.6 .Theoretical isoelectric point of the protein was 5.86 .It was predicted that the CRTISO in D.viridis was properly targeted to the cytoplasmic matrix .Compared with a-mino acid sequences in NCBI database , it was found that the amino acid sequence of CRTISO shared the highest homology with Chlo-rella variabilis (78%).RT-qPCR showed that the transcription level of crtiso reached the maximum when the concentration of AA got 62.5 mg/L and ASA reached 50 mg/L.The result of carotenoid content showed that the carotenoid content reached the maximum when the concentration of AA got 312.5 mg/L and ASA reached 100 mg/L.There was certain correlation between the expression of crtiso gene and the content of carotenoids .%类胡萝卜素异构酶（ Carotenoid isomerase ， CRTISO）是类胡萝卜素生物合成途径中催化番茄红素由顺式结构向反式结构转变的关键异构酶。利用转录组测序获得绿色杜氏藻crtiso cDNA全长序列，进行生物信息学分析，并研究乙酰水杨酸（ ASA）、花生四烯酸（ AA）处理绿色杜氏藻后该基因转录差异与类胡萝卜素含量变化情况。生物信息学结果表明：绿色杜氏藻crtiso cDNA全长1176 bp，开放阅读框（ ORF）长度为795 bp，编码264个氨基酸。该蛋白质的理论相对分子质量为29522.6，理论等电点（PI）为5.86，该蛋白为稳定蛋白与亲水性蛋白，无信号肽和跨膜区域，定位于细胞质基质。氨基酸序列同源性比对结果表明其与小球藻的类胡萝卜素异构酶同源性最高，达到78％。 RT-qPCR结果表明，AA、ASA诱导后，该基因表达量均呈现先升高后降低的趋势，且当AA、ASA质量浓度分别为62.5 mg／L、50 mg／L时表达量最高。类胡萝卜素含量大致呈现逐渐升高的趋势。当AA、ASA质量浓度分别为312.5 mg／L、100 mg／L时，类胡萝卜素含量达到最高。即该基因与类胡萝卜素含量呈一定相关性。
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