Abstract: Cinnamate-4-hydroxylase (C4H) has an important role in the regulation of plant growth and development. To investigate the molecular regulatory mechanism of flavonoid synthesis in Hedysarum polybotrys,the HpC4H gene was cloned from Hedysarum polybotrys seedlings by the RACE technique,and its bioinformation and expression patterns were analyzed in this study. The results showed that the full length of HpC4H was 1634 bp in length which encodes 477 amino acids. The molecular weight of the HpC4H protein was 54.94 kD. The HpC4H protein structure did not contain signal peptides and transmembrane structural regions. Subcellular localization prediction showed that the HpC4H protein was located in the endoplasmic reticulum. It had a C4H-conserved functional region and belonged to the cytochrome P450 supergene family. The amino acid sequence of HpC4H showed the highest similarity of 92.84% with Caragana korshinskii. The results of qRT-PCR showed that the HpC4H gene was predominantly expressed in roots,followed by stems and leaves. At the same time,the expression of this gene was up-regulated under the intervention of different concentrations of iron salt. This study speculated that different concentrations of iron salts might play a certain role in regulating the expression of the HpC4H gene in Hedysarum polybotrys,and the low iron salt solution had a significant effect.

Key words: Hedysarum polybotrys Hand.-Mazz., Cinnamate-4-hydroxylase, Gene clone, Iron salt solution, Gene expression

摘要： 肉桂酸-4-羟化酶(Cinnamate-4-hydroxylase，C4H)在调节植物生长发育方面具有重要的作用。为探究红芪(Hedysarum polybotrys Hand.-Mazz.)黄酮类成分合成的分子调节机制，本研究以红芪幼苗为材料，通过RACE技术，克隆HpC4H基因，并进行生物信息学分析和表达模式分析。结果显示：HpC4H基因全长为1634 bp，编码477个氨基酸，蛋白分子量为54.94 kD，不含有信号肽和跨膜结构区。亚细胞定位预测显示，该蛋白定位于内质网中，具有C4H保守功能区并属于细胞色素P450超基因家族。序列分析发现，HpC4H氨基酸序列与柠条锦鸡儿(Caragana korshinskii Kom.)的相似性高达92.84%。qRT-PCR结果表明，HpC4H基因在红芪不同组织中的表达模式为：根>茎>叶，同时，该基因的表达量在不同浓度铁盐干预下有上调趋势，推测铁盐可能在调控红芪HpC4H基因表达中发挥一定作用，且低浓度铁盐溶液作用显著。

关键词: 红芪, 肉桂酸-4-羟化酶, 基因克隆, 铁盐溶液, 基因表达