CAJ | 학술논문

西藏胡黄连是著名的濒危西藏药材, 其粗壮的根茎部是重要的合成和储存药用萜类物质器官,萜类含量显著高于叶部.为克隆西藏胡黄连根状茎和叶的差异表达基因,利用抑制消减杂交技术,构建了根状茎特定的抑制消减文库.从该SSH文库中随机挑取片段不一的阳性克隆测序,采用Blastx进行同源比对,获得了27个表达序列标签(EST),并获登录号.序列统计分析结果表明,其中有11个EST在GenBank中无同源性序列,推测可能是新基因片断.蛋白质功能分类结果表明,这些蛋白质与翻译、能量代谢、转运与结合、细胞膜合成、氨基酸生物合成及中间代谢6大类蛋白功能有关.为深入研究与萜类生物合成直接或间接相关基因,选择了长595 bp的差异表达EST序列EX172715进行了同源比对和蛋白系统进化分析.结果表明,EX172715具有细胞色素P450单加氧酶的特征结构,与拟南芥的细胞色素P450单加氧酶蛋白的同源性高于水稻和小麦.提供了一组与西藏胡黄连次生代谢相关的新基因库.
서장호황련시저명적빈위서장약재, 기조장적근경부시중요적합성화저존약용첩류물질기관,첩류함량현저고우협부.위극륭서장호황련근상경화협적차이표체기인,이용억제소감잡교기술,구건료근상경특정적억제소감문고.종해SSH문고중수궤도취편단불일적양성극륭측서,채용Blastx진행동원비대,획득료27개표체서렬표첨(EST),병획등록호.서렬통계분석결과표명,기중유11개EST재GenBank중무동원성서렬,추측가능시신기인편단.단백질공능분류결과표명,저사단백질여번역、능량대사、전운여결합、세포막합성、안기산생물합성급중간대사6대류단백공능유관.위심입연구여첩류생물합성직접혹간접상관기인,선택료장595 bp적차이표체EST서렬EX172715진행료동원비대화단백계통진화분석.결과표명,EX172715구유세포색소P450단가양매적특정결구,여의남개적세포색소P450단가양매단백적동원성고우수도화소맥.제공료일조여서장호황련차생대사상관적신기인고.
Picrorhiza scrophulariiflora is a rare and endangered Tibetan medicinal plant. Its rhizome is a specific biosynthesis and accumulation tissue for invaluable hepatoprotective iridoids. We applied SSH technique for elucidating the differential gene expression in rhizome and leaf of the plant and constructed a subtracted rhizomE-specific cDNA library. From the library, 27 non-redundant "EST-unigenes" were obtained and submitted to dbEST. Sequence analysis showed that 11 ESTs among the 27 ESTs are deducted to be novel genes (ESTs) with no significant homology to any known sequences within GenBank database and could potentially be regarded as novel gene fragments. These 27 ESTs are mainly associated with translation, energy metabolism, transport and binding, cell envelope, amino acid biosynthesis, and central intermediary metabolism. Finally, phylogenetic analyses implicated that a cytochrome monooxygenase P450-related gene (EX172715, 595 bp) identified from P. scrophulariiflora are more related to that from A. thaliana than that from O.sativa and T.aestivum. This study provides a novel gene pool involved in P.scrophulariiflora secondary metabolism.