罗汉果色氨酸转氨酶基因SgTAR2的克隆及表达分析

发布时间：2018-11-27 06:36

【摘要】：色氨酸转氨酶基因家族,是直接参与植物生长素生物合成途径的关键酶基因。该研究在罗汉果转录组测序的基础上,结合RACE技术克隆罗汉果色氨酸转氨酶基因SgTAR2的全长cDNA序列和DNA序列;并对其进行生物信息学分析和时空表达分析。结果表明:克隆所得SgTAR2的cDNA全长序列2078bp,最长ORF为1332bp,编码443个氨基酸,Gen Bank登录号为KU949381,其编码蛋白具有2个蒜氨酸酶保守结构域和多个5'-PLP结合位点,推测其可能参与催化色氨酸转氨基作用、化学防御作用、生长素生物合成等生物学过程;SgTAR2基因DNA长为4103bp,含有4个内含子和5个外显子,其内含子具有多个高水平转录调控因子和多个与激素、环境等胁迫响应相关的作用元件,暗示SgTAR2基因内含子协同调控罗汉果生长素合成、抗胁迫反应、形态发育等生物学过程。实时荧光定量结果显示,SgTAR2基因在罗汉果各组织器官均有表达,在雌蕊和15d幼果期表达量较高,暗示该基因参与罗汉果果实早期发育。该研究结果表明SgTAR2参与了生长素介导的罗汉果不同生长发育过程,特别对幼果及花的起始发育和器官形态建成等具有重要意义。
[Abstract]:Tryptophan transaminase gene family is a key enzyme gene directly involved in the biosynthesis of plant auxin. In this study, the full-length cDNA and DNA sequences of the tryptophan aminotransferase gene (SgTAR2) of Luohanguo were cloned based on the transcriptome sequencing of Luohanguo, and their bioinformatics and spatio-temporal expression were analyzed. The results showed that the full-length cDNA sequence of the cloned SgTAR2 was 2078 BP, the longest ORF was 1332 BP, and the 443 amino acid, Gen Bank accession number was KU949381,. The encoded protein had two alliinase conserved domains and multiple 5'-PLP binding sites. It may be involved in the biological processes of catalytic tryptophan transamino action chemical defense and auxin biosynthesis. The DNA length of SgTAR2 gene is 4103 BP, which contains 4 introns and 5 exons. The intron has many high level transcription regulators and many related elements related to stress response, such as hormone, environment, etc. It is suggested that the intron of SgTAR2 gene co-regulates the biosynthesis of auxin, anti-stress response, morphological development and other biological processes. The results of real-time fluorescence quantitative analysis showed that SgTAR2 gene was expressed in all tissues and organs of Siraitia grosvenori, and was higher in pistil and 15d young fruit, suggesting that SgTAR2 gene was involved in the early development of Siraitia grosvenorii fruit. The results showed that SgTAR2 was involved in the auxin mediated growth and development of Siraitia grosvenori, especially in the initiation and development of young fruits and flowers and organ morphogenesis.
【作者单位】：广西大学农学院;九江市第三人民医院;广西药用植物园广西药用资源保护与遗传改良重点实验室;
【基金】：国家自然科学基金(31260359) 广西大学博士启动项目(XBZ110586)~~
【分类号】：Q943.2;S668.9

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