Phylogenetic relationship in the genus Panax: inferred from chloroplast trnK gene and nuclear 18S rRNA gene sequences

Chloroplast trnK gene and nuclear 18S rRNA gene sequences of 13 Panax taxa, collected mainly from Sino-Japanese floristic region, were investigated in order to construct phylogenetic relationship and to assist taxonomic delimitation within this genus. The length of trnK gene sequence varied from 2537 bp to 2573 bp according to the taxa, whereas matK gene sequences, embedded in the intron of trnK gene, were of 1512 bp in all taxa. Species-specific trnK/ matK sequence provided much insight into phylogeny and taxonomy of this genus. 18S rRNA gene sequences were of 1808 or 1809 bps in length, only 9 types of 18S rRNA sequences were observed among 13 taxa. Parsimony and neighbor-joining analyses of the combined data sets of trnK-18S rRNA gene sequences yielded a well-resolved phylogeny within genus Panax, where three main clades were indicated. P. pseudoginseng and P. stipuleanatus formed a sister group located at a basal position in the phylogenetic tree, which suggested the relatively primitive position of these two species. Monophyly of P. ginseng, P. japonicus (Japan) and P. quinquefolius, which are distributed in northern parts of Asia or America, was well supported (Northern Clade). The remaining taxa distributed in southern parts of Asia formed a relatively large clade (Southern Clade). The taxonomic debated taxa traditionally treated as subspecies or varieties of P. japonicus or P. pseudoginseng showed various nucleotide sequences, but all fell into one cluster. It might suggest these taxa are differentiated from a common ancestor and are in a period of high variation, which is revealed not only on morphological appearance, but also on molecular divergence. By comparing trnK and 18S rRNA gene sequences among 13 Panax taxa, a set of valuable molecular evidences for identification of Ginseng drugs was obtained.     

6种川产姜黄属药用植物叶绿体trnK基因序列变异分析及其分子鉴定

目的建立6种川产姜黄属(Curcuma)药用植物快速简单的分子鉴定方法.方法采用叶绿体赖氨酸tRNA基因(trnK)测序与序列变异分析方法.结果 6种姜黄属药用植物(包括姜黄C. longa、莪术C. phaeocaulis、川郁金C. sichuanensis、川郁金C. chuanyujin、川黄姜C. chuanhuangjiang、川莪术C. chuanezhu)完整trnK基因长度在2699～2705 bp.序列可变区包括matK基因编码区和trnK外显子与matK内含子之间区域,共有6个单核苷酸多态性(SNPs)位点、1个9-bp的缺失重复序列和2个4-bp、14-bp插入重复序列.结论 trnK基因序列可变位点可以作为6种川产姜黄属药用植物快速简单的分子鉴定标记,并为它们之间种的归并提供了分子依据.     

Sequence analysis of Chinese and Japanese Curcuma drugs on the 18S rRNA gene and trnK gene and the application of amplification-refractory mutation system analysis for their authentication

The botanical origins of Chinese and Japanese Curcuma drugs were determined to be Curcuma longa, C. phaeocaulis, the Japanese population of C. zedoaria, C. kwangsiensis, C. wenyujin, and C. aromatica based on a comparison of their 18S rRNA gene and trnK gene sequences with those of six Curcuma species reported previously. Moreover, to develop a more convenient identification method, amplification-refractory mutation system (ARMS) analysis of both gene regions was performed on plants. The ARMS method for the 18S rRNA gene was established using two types of forward primers designed based on the nucleotide difference at position 234. When DNAs of four Curcuma species were used as templates, PCR amplification with either of the two primers only generated a fragment of 912 base pairs (bp). However, when DNAs of the purple-cloud type of C. kwangsiensis and C. wenyujin were used, PCR amplifications with both primers unexpectedly generated the fragment, suggesting that these two were heterozygotes. The ARMS method for the trnK gene was also established using a mixture of four types of specific reverse primers designed on the basis of base substitutions and indels among six species, and common reverse and forward primers. C. phaeocaulis or the Chinese population of C. zedoaria, the Japanese population of C. zedoaria or the purple-cloud type of C. kwangsiensis, the pubescent type of C. kwangsiensis or C. wenyujin, and C. aromatica were found to show specific fragments of 730, 185, 527 or 528, and 641 or 642 bp, respectively. All species including C. longa also showed a common fragment of 897-904 bp. Using both ARMS methods, together with information on producing areas, the identification of Curcuma plants was achieved. Moreover, the ARMS method for the trnK gene was also useful for authentication of Curcuma drugs.     

6种川产姜黄属药用植物叶绿体trnK基因序列变异分析及其分子鉴定

目的建立6种川产姜黄属（Curcuma）药用植物快速简单的分子鉴定方法。方法采用叶绿体赖氨酸tRNA基因（trnK）测序与序列变异分析方法。结果6种姜黄属药用植物（包括姜黄C. longa、莪术C. phaeocaulis、川郁金C. sichuanensis、川郁金C. chuanyujin、川黄姜C. chuanhuangjiang、川莪术C. chuanezhu）完整trnK基因长度在2699～2705 bp。序列可变区包括matK基因编码区和trnK外显子与matK内含子之间区域，共有6个单核苷酸多态性（SNPs）位点、1个9-bp的缺失重复序列和2个4-bp、14-bp插入重复序列。结论trnK基因序列可变位点可以作为6种川产姜黄属药用植物快速简单的分子鉴定标记，并为它们之间种的归并提供了分子依据。     

Molecular analysis of medicinally-used Chinese and Japanese Curcuma based on 18S rRNA gene and trnK gene sequences.

Curcuma drugs have been used discriminatingly for invigorating blood circulation, promoting digestion, and as a cholagogic in China. However, there is confusion about the drug's botanical origins and clinical uses because of morphological similarity of Curcuma plants and drugs. In order to develop an ultimate identification, molecular analysis based on 18S rRNA gene and trnK gene sequences were performed on 6 Curcuma species used medicinally in China and Japan. The 18S rRNA gene sequences were found to be of 1810 bps in length. In comparison with the common sequence of C. longa, C. phaeocaulis, C. wenyujin and C. aromatica, that of C. kwangsiensis had one base substitution, and the same base difference was observed between the Chinese and the Japanese populations of C. zedoaria. The trnK gene sequences were found to span 2698-2705 bps. There were base substitutions, small deletions or insertions at some sites between the trnK coding region and matK region among each species. Based on the base substitutions, C. zedoaria and C. kwangsiensis specimens were divided into two groups, respectively. An identical sequence was detected in C. phaeocaulis and in the Chinese population of C. zedoaria, as well as in the Japanese population of C. zedoaria and in one group of C. kwangsiensis with a purple-colored band in leaves. New taxonomic information to be used for authenticating Curcuma drugs was obtained.     

Species identification from Ginseng drugs by multiplex amplification refractory mutation system (MARMS)

The multiplex amplification refractory mutation system (MARMS) was applied to the identification of 5 Panax species ( P. ginseng, P. japonicus, P. quinquefolius, P. notoginseng and P. vietnamensis). A set of specific primers, including 2-pair primers on chloroplast trnK gene and nuclear 18S rRNA gene regions, respectively, was designed and synthesized for each species on the basis of species-specific sequences of the 2 genes. By using 5 sets of specific primers, in turn, PCR amplifications were performed with total DNA extracted from 5 Panax species as template under appropriate condition, and each resulting product was detected by agarose gel electrophoresis. The results showed that two expected fragments, one from trnK gene and another from 18S rRNA gene regions, were observed simultaneously only when the set of species-specific primers encountered template DNA of the corresponding species. This assay could give more reliable results for identification of not only 5 Panax species but also corresponding Ginseng drugs by simultaneous detection of 4-site nucleotide differences on 2 completely different genes.     

Application of single-nucleotide polymorphism analysis of the trnK gene to the identification of Curcuma plants

We previously found that Curcuma plants and drugs derived from Curcuma longa, C. phaeocaulis, C. zedoaria, and C. aromatica could be identified by the nucleotide differences at two sites and the existence of a 4-base indel on trnK gene. In this paper, based on species-specific nucleotide sequences, the application of a new method, single-nucleotide polymorphism (SNP) analysis was investigated to identify Curcuma plants more conveniently. First, three types of reverse primer were synthesized in different lengths, 34 mer, 26 mer, and 30 mer, to anneal the template DNAs from each species at sites immediately upstream from substitution positions 177 and 645, and at the site including the 4-base insertion from 728 to 731, respectively. After single-base extension reaction of these primers using fluorescent-labeled ddNTPs and PCR products of the trnK gene region as template, the resulting products were detected using an ABI PRISM 310 Genetic Analyzer. The electrophoretogram showed three or two peaks at different positions depending on the 27 mer, 31 mer, and 35 mer product lengths. Each peak was derived from the incorporated fluorescent-labeled ddNMPs complementary to template nucleotides at positions 645, 724, and 177, respectively. C. phaeocaulis showed three peaks of ddCMP, ddAMP, and ddAMP. The other three species showed two peaks derived from 27 mer and 35 mer products: peaks of ddCMP and ddAMP in C. longa, those of ddCMP and ddTMP in C. zedoaria, and those of ddTMP and ddAMP in C. aromatica. Thus SNP analysis to identify four Curcuma plants was newly developed.     

Identification of the crude drug atractylodes rhizome (Byaku-jutsu) and atractylodes lancea rhizome (So-jutsu) using chloroplast TrnK sequence as a molecular marker

Novel methods for molecular authentication of Atractylodes-derived crude drugs (Jutsu) were established based on PCR-restriction fragment length polymorphism (RFLP) and direct sequencing of chloroplast trnK. Two regions inside the chloroplast trnK were selected as molecular markers for identification and discrimination of Atractylodes Rhizome (Byaku-jutsu) and Atractylodes Lancea Rhizome (So-jutsu). The Region 1 fragment (260 bp) amplified from So-jutsu and Wa-byaku-jutsu (Atractylodes Rhizome derived from A. japonica) gave 2 bands of 180 bp and 80 bp on agarose gel electrophoresis after digestion with a restriction endonuclease HinfI, whereas the fragment amplified from Kara-byaku-jutsu (Atractylodes Rhizome derived from A. ovata) remained undigested, which allowed unambiguous identification of Kara-byaku-jutsu. By direct sequencing of Region 2 (436 bp) and comparison of the nucleotide sequence data sets we could not only discriminate Byaku-jutsu and So-jutsu but also identify the original plant species of each crude drug specimen. A simple and reliable protocol for rapid preparation of DNA suitable for PCR from as little as 1 mg of Atractylodes-derived crude drugs was also described.     

中国不同地区蛇床的rDNA ITS序列分析

目的：探讨不同分布区的蛇床Cnidium monnieri的ITS序列变异与其地理分布和化学成分的相关性。方法：设计2对引物,Pf+Pb及P5.8S ITS1+P5.8S ITS2,PCR扩增产物纯化后用银染法或ABI 310测序。结果：得到核糖体DNA中的ITS及5.8S rDNA完全序列,18S和26S rDNA部分序列,共约700 bp。5个地点样品的ITS-1及ITS-2的序列大小分别为210～217 bp和219～224 bp。ITS-1碱基序列的遗传距离0.00～1.93%,ITS-2碱基序列的遗传距离0.46～2.34%,ITS-1较为保守。以NJ法根据ITS-2序列数据重建系统发生树。哈尔滨样品聚为一组,衡水与德州样品和郑州与高淳样品各自聚为一组。结论：ITS-2序列的变异与中国产蛇床的纬度分布相关,而其与蛇床化学型的关系尚需作进一步研究。     

广藿香与土藿香的DNA序列分析及其分子鉴别

目前市场上藿香类商品药材有两种 ,一种为唇形科刺蕊草属 (Ｐｏｇｏｓｔｅｍｏｎ)植物广藿香Ｐｏｇｏｓｔｅｍｏｎｃａｂｌｉｎ (Ｂｌａｎｃｏ)Ｂｅｎｔｈ.的干燥地上部分 ,主产广东、海南 ,习称“广藿香”,均为栽培品 ,有芳香化浊、开胃止呕、发表解暑的功效 ,是中成药“藿香正气水”的主要原料。据我们分析广州市郊黄村产“石牌广藿香”药材茎枝挥发油成分 ,其中 71 %为广藿香酮(ｐｏｇｏｓｔｏｎｅ) [1 ] ;另一种来源于同科另一属 ,即藿香属(Ａｇａｓｔａｃｈｅ)植物藿香Ａｇａｓｔａｃｈｅｒｕｇｏｓａ (Ｆｉｓｃｈ.ｅｔＭｅｙ.)Ｏ .Ｋ…     

紫苏属药用植物的rDNA ITS区SNP分子标记与位点特异性PCR鉴别

目的分析单种属——紫苏属各变种间rDNA ITS区的序列以及存在的单核苷酸多态性(SNP)现象，设计出位点特异性PCR引物，用于紫苏属各变种间的分子标记鉴别。方法对紫苏属各变种多个体的rDNA ITS区全序列进行了准确测定，运用Clustral X 1.8，MEGA 3.0进行排序并进行SNP分析，从而设计出鉴别各变种的等位基因位点特异性PCR鉴别引物。结果紫苏属各变种(紫苏、白苏、鸡冠苏和耳齿紫苏等)的rDNA ITS区全序列共有615～618 bp的长度，ITS1为233～235 bp，5.8S为179 bp，ITS2为203～204 bp，GC含量为61.5%～61.9%。从rDNA ITS区碱基变异的整体情况来看，紫苏属各变种间不仅在非编码的转录间隔区ITS1和ITS2内存在非编码区单核苷酸多态性(ncSNP)，而且在保守的5.8S编码区内也存在3个位点的单核苷酸多态性，即编码区SNP(cSNP)，所有的SNP均只具2等位多态性。5.8S区cSNP的出现与产生该变异的变种出现的显著形态差异关联。本文还利用这些SNP位点设计出了鉴别紫苏属各变种的位点特异性PCR引物，无需测序即可对紫苏属的原植物及“苏子”、“苏叶”等药材进行有效准确的分子鉴别。结论紫苏属药用植物rDNA ITS区存在的SNP可用作紫苏属各变种鉴别的分子标记。     

Molecular analysis of the genus Mitragyna existing in Thailand based on rDNA ITS sequences and its application to identify a narcotic species: Mitragyna speciosa

In Thailand, there are four Mitragyna species; M. speciosa, M. hirsuta, M. diversifolia, and M. rotundifolia. One, M. speciosa, is a narcotic plant and has medicinal importance for its opium-like effect. Since the use of M. speciosa has been forbidden in Thailand, the leaves of M. diversifolia or others are frequently used as substitutes but are not considered as effective. Therefore, accurate authentication of M. speciosa is essential for both medicinal and forensic purposes. The nucleotide sequences of internal transcribed spacers (ITS) and the 5.8S coding region of nuclear ribosomal DNA (rDNA) of the Mitragyna species were analyzed. The whole length of ITS1-5.8S-ITS2 region was 608 bp in M. speciosa, 607 bp in the other species. Nineteen sites of nucleotide substitutions and 3 sites of 1-bp indels were observed, and M. speciosa showed specific sequence differed from the others. Based on the ITS sequences, a distinctive site recognized by a restriction enzyme XmaI in M. speciosa was found and then PCR-restriction fragment length polymorphism (RFLP) analysis was established to differentiate M. speciosa from the others. By the method, a 409-bp PCR fragment of ITS1-5.8S (partial) rDNA region from M. speciosa was cleaved into two fragments of 119 bp and 290 bp while the other species remained undigested. This method provides an effective and accurate identification of M. speciosa.     

不同产地蒺藜核糖体DNA内转录间隔区序列分析

目的通过测定核糖体DNA内转录间隔区(Ribosomal DNA internal transcribed spacer,rDNA-ITS)基因序列,确定不同产地的蒺藜在种质遗传上是否存在差异。方法利用PCR产物直接测序,测定不同产地蒺藜的rDNA-ITS基因序列。结果测得ITS碱基序列742 bp,其中ITS1全部序列267 bp,5.8 S全部序列167bp,ITS2全部序列209 bp。6个产地的蒺藜样品的ITS的碱基序列完全相同。结论不同地区的蒺藜在种质上没有发生变异。     

Molecular identification of "Chuanxiong" by nucleotide sequence and multiplex single base extension analysis on chloroplast trnK gene

Chloroplast trnK gene sequences of Cnidium officinale and Ligusticum chuanxiong were determined to establish an effective method for identifying Japanese Senkyu and Chinese Chuanxiong, the two which have the same drug name in Chinese characters, similar external feature, but different botanical origins. Three sites of nucleotide differences were found between these 2 species at positions 767,924 and 964 from upstream in trnK gene sequence, allowing molecular identification of the two plants and crude drugs. Further, three kinds of specific primers of 14 mer, 23 mer and 30 mer long were designed to detect these 3 sites of marker nucleotides. By using multiplex single base extension (MSBE) analysis with the 3 specific primers, C. officinale and L. chuanxiong could be distinguished clearly by the electrophoretograms, where 3 peaks with different color of ddTMP, ddCMP and ddTMP were observed in case of C. officinale and those of ddGMP, ddAMP and ddGMP in L. chuanxiong. Moreover, trnK gene sequence of "Dongxiong," a kind of Chuanxiong cultivated in Northeast China, suggested that its botanical origin was C. officinale.     

中日产川芎的matK、ITS基因序列及其物种间的亲缘关系

目的分析中国产川芎Ligusticum chuanxiong Hort.及日本产川芎Cnidium officinale Makino的核基因组ITS和叶绿体基因组matK序列,为探讨中日产川芎物种间的亲缘关系提供分子依据。方法采用PCR直接测序技术测定川芎和日本川芎的ITS基因和matK基因核苷酸序列并作序列变异分析。结果川芎和日本川芎的matK序列长度均为1268 bp,编码422个氨基酸。ITS1-5.8S-ITS2序列长度均为699 bp,其中18S rRNA基因3′端序列54 bp,ITS1序列215 bp,5.8S rRNA基因序列162 bp,ITS2序列222 bp,26S rRNA基因5′端序列46 bp。根据排序比较,川芎原植物与其商品药材间的matK基因和ITS基因序列完全相同,而川芎与日本川芎间matK基因则仅有1个变异位点,即在上游959 nt处1个转换替代(T→C),反映在氨基酸序列则发生一个非同义取代V(GTG)→A(GCG);ITS基因也仅有1个变异位点,即在ITS1上游54 nt处1个转换替代(T→C)。结论通过进化速率较快的基因序列同源性分析,基本可以认为中日所产川芎基原一致,日本川芎学名似应改为Ligusticum chuanxiong Hort.。     

男性泌尿生殖道感染患者分离奈瑟菌的16S rDNA和PIA基因检测

目的检测男性泌尿生殖道分离奈瑟菌的16SrDNA和PIA基因,探讨奈瑟菌属菌种的基因鉴定及其致病机理。方法用PCR扩增和核苷酸序列分析方法分别检测11例男性泌尿生殖道感染患者泌尿生殖道分离的14株奈瑟菌属菌种的16SrDNA和PIA基因及其序列。结果 14株奈瑟菌属菌种经16SrDNA检测鉴定分别为淋病奈瑟菌2株,黏液奈瑟菌3株,灰色奈瑟菌5株,微黄奈瑟菌2株,干燥奈瑟菌1株,嗜乳糖奈瑟菌及多糖奈瑟菌各1株;与常规细菌学方法鉴定的符合率为85.7%。非淋球菌奈瑟菌未检出淋病奈瑟菌毒力相关的PIA核苷酸序列。结论常规细菌学方法与染色体16SrDNA检测及其序列分析方法的联合使用,可提高奈瑟菌属菌种感染的实验室诊断准确率;PIA基因对于奈瑟菌属的男性生殖道致病性无关。     

Phylogenetic analysis based on 18S rRNA gene and matK gene sequences of Panax vietnamensis and five related species

Panax vietnamensis was discovered recently in Vietnam. Its bamboo-like rhizomes, called Vietnamese Ginseng, have attracted considerable attention because of their specific pharmacological activities. In order to define the taxonomic position of this new species and include it in the molecular authentication of Ginseng drugs, the 18S ribosomal RNA gene and matK gene sequences of P. vietnamensis were determined and compared with those of its related taxa, P. japonicus var. major and P. pseudo-ginseng subsp. himalaicus, besides previously reported P. ginseng, P. japonicus and P. quinquefolius. The 18S rRNA gene sequences were found to be 1809 bps in length. The sequence of P. vietnamensis was identical to that of P. quinquefolius, and presented one base substitution from those of both P. japonicus var. major and P. pseudo-ginseng subsp. himalaicus. The matK gene sequences of 6 taxa were found to be 1509 bps in length. The sequence of P. vietnamensis differed from those of P. japonicus var. major, P. pseudo-ginseng subsp. himalaicus, P. ginseng, P. japonicus and P. quinquefolius at 4, 5, 9, 9 and 10 nucleotide positions, respectively. The phylogenetic tree reconstructed by the combined 18S rRNA-matK gene analysis using the maximum parsimony method showed that P. vietnamensis was sympatric with other Panax species and had a close relationship with P. japonicus var. major and P. pseudo-ginseng subsp. himalaicus.     

Authentication of stems of Dendrobium officinale by rDNA ITS region sequences

The rDNA ITS regions of five Dendrobium species were sequenced. Each Dendrobium species was found to have a unique sequence in the ITS region, so that they could be easily distinguished at the DNA level. The aligned 644 bp of the ITS region includes 235 bp ITS1, 163 bp 5.8S, and 246 bp ITS2. One hundred and eighty-nine sites are variable. The sequences of D. officinale could be easily distinguished from the other four adulterant species according to the sequence variation at 11 sites, 7 in ITS1, 1 in 5.8S, and 3 in ITS2. These could be used as molecular characters to distinguish the stems of D. officinale from the adulterants.     

Widespread distribution of tetracycline resistance genes in a confined animal feeding facility

We sought to determine the distribution of resistance and the tetracycline resistance genes among bacteria isolated from a swine confined animal feeding facility where tetracycline-containing feed had been in use for over 20 years. Samples collected from feed, hogs, hog houses, waste lagoon, soil, surface water and well water were screened for the presence of (a) resistant Escherichia coli and enterococci and (b) tetracycline-resistant strains of all species. Genomic DNA was extracted from the latter strain collection and fragments from 16S rDNA and ten tetracycline resistance genes (tetA, tetB, tetC, tetE, tetH, tetL, tetM, tetS, tetT and rumB) were polymerase chain reaction-amplified and a partial nucleotide sequence was obtained. In this environment, 77% of E. coli and 68% of enterococci isolated were tetracycline resistant. Tetracycline resistance was found in 26 different bacterial genera and in 60 species. Single resistance gene alleles (as defined by nucleotide sequence) were present in multiple species. There was evidence of gene recombination and multiple different tetracycline resistance genes were present in single bacterial isolates. These data provide further evidence for the widespread distribution of resistance genes in microbial populations in settings in which there is ongoing subtherapeutic antimicrobial use.     

Rapid identification of Curcuma longa and C. aromatica by LAMP

We have developed a novel method for the identification of Curcuma longa and C. aromatica called "loop-mediated isothermal amplification (LAMP)," based on trnK gene sequences. LAMP employs four primers that recognize six regions on the target DNA. Cycling elongation was initiated when the four primers were annealed to the target DNA. Amplifications were detected by measuring turbidity due to the formation of magnesium pyrophosphate. We designed allele-specific primer sets for C. longa and C. aromatica, respectively. LAMP using a primer set for C. longa and total DNA extracted from C. longa rhizome (0.5-10.0 ng) as template was detected up to 70 min. On the other hand, in the reaction using a primer set for C. longa and total DNA from C. aromatica as template, no amplifications were detected. The same tendency could be seen in the reactions using a set of primers for C. aromatica. LAMP enabled not only identification but also detection with high specificity. This rapid, specific, sensitive, and convenient method is expected to be applicable to the identification of the botanical origin of commercially available herbal products.