Institute of Medicinal Plant Development (IMPLAD), Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
PLoS One. 2013 Apr 25;8(4):e62922. doi: 10.1371/journal.pone.0062922. Print 2013.
Lonicera japonica Thunb. is a plant used in traditional Chinese medicine known for its anti-inflammatory, anti-oxidative, anti-carcinogenic, and antiviral pharmacological properties. The major active secondary metabolites of this plant are chlorogenic acid (CGA) and luteoloside. While the biosynthetic pathways of these metabolites are relatively well known, the genetic information available for this species, especially the biosynthetic pathways of its active ingredients, is limited.
METHODOLOGY/PRINCIPAL FINDINGS: We obtained one million reads (average length of 400 bp) in a whole sequence run using a Roche/454 GS FLX titanium platform. Altogether, 85.69% of the unigenes covering the entire life cycle of the plant were annotated and 325 unigenes were assigned to secondary metabolic pathways. Moreover, 2039 unigenes were predicted as transcription factors. Nearly all of the possible enzymes involved in the biosynthesis of CGA and luteoloside were discovered in L. japonica. Three hydroxycinnamoyl transferase genes, including two hydroxycinnamoyl-CoA quinate hydroxycinnamoyl transferase genes and one hydroxycinnamoyl-CoA shikimate/quinate hydroxycinnamoyl transferase (HCT) gene featuring high similarity to known genes from other species, were cloned. The HCT gene was discovered for the first time in L. japonica. In addition, 188 candidate cytochrome P450 unigenes and 245 glycosyltransferase unigenes were found in the expressed sequence tag (EST) dataset.
This study provides a high quality EST database for L. japonica by 454 pyrosequencing. Based on the EST annotation, a set of putative genes involved in CGA and luteoloside biosynthetic pathways were discovered. The database serves as an important source of public information on genetic markers, gene expression, genomics, and functional genomics in L. japonica.
忍冬是一种在传统中药中使用的植物，具有抗炎、抗氧化、抗癌和抗病毒的药理作用。该植物的主要活性次生代谢产物是绿原酸（CGA）和木犀草苷。虽然这些代谢物的生物合成途径相对较为明确，但该物种的遗传信息，特别是其活性成分的生物合成途径的信息有限。
方法/主要发现：我们使用罗氏/454 GS FLX 钛平台进行全序列运行，获得了一百万条读数（平均长度为 400bp）。总共，覆盖植物整个生命周期的 85.69%的基因被注释，325 个基因被分配到次生代谢途径中。此外，2039 个基因被预测为转录因子。在忍冬中几乎发现了参与 CGA 和木犀草苷生物合成的所有可能的酶。克隆了三个羟基肉桂酰基转移酶基因，包括两个羟基肉桂酰辅酶 A 奎尼酸羟基肉桂酰基转移酶基因和一个羟基肉桂酰辅酶 A 莽草酸/奎尼酸羟基肉桂酰基转移酶（HCT）基因，与其他物种的已知基因具有高度相似性。首次在忍冬中发现了 HCT 基因。此外，在表达序列标签（EST）数据集中共发现了 188 个候选细胞色素 P450 基因和 245 个糖基转移酶基因。
本研究通过 454 焦磷酸测序为忍冬提供了高质量的 EST 数据库。基于 EST 注释，发现了一组可能参与 CGA 和木犀草苷生物合成途径的基因。该数据库为忍冬的遗传标记、基因表达、基因组学和功能基因组学提供了重要的公共信息来源。
