药用植物基因组及EST研究

以生物信息学数据库GenBank的生物信息为基础 ,对包括《中国药典》2 0 0 0年版一部、《新编中药志》第 1～ 3卷、《中国大百科全书》(中国传统医学分册 )、中国医学科学院药物研究所编写的《中草药现代研究》及《天然药物化学》第三版中所涉及的 2 30 0多种药用植物的基因组、蛋白质及表达序列标签 (EST)的注册情况进行了初步统计 ,就相关进展进行了综述。到 2 0 0 3年 9月底截止的数据分析表明 ,66%的药用植物没有核酸序列报道 ,77%的药用植物没有蛋白质序列注册。进行药用植物基因组研究的植物与国家十分有限 ,而进行药用植物EST研究的国家相对较多 ,涉及的植物也相对集中 。     

miRNA调控药用植物生长发育和次生代谢

microRNA(miRNA)作为一类内源性的短链非编码RNA,广泛存在于真核细胞中,主要通过对转录本剪切和抑制翻译等方式,参与转录后基因的表达调控。近年来研究表明,多种药用植物中鉴定出大量的miRNA。这些miRNA对药用植物的生长发育和次生代谢产物合成具有调控功能。次生代谢产物是药用植物的主要有效成分,研究miRNA对药用植物次生代谢过程的调控作用具有十分重要的意义。本文综述了miRNA在植物中的产生途径、作用方式和体内功能,在此基础上重点介绍了miRNA对药用植物生长发育和次生代谢产物生物合成的调控作用,并对药用植物miRNA的研究进行了展望,以期为提高药用植物产量,高效获得药用植物有效成分以及临床应用开拓新的思路。     

植物挥发性物质及其代谢工程

植物挥发性物质在植物之间和植物与昆虫间的化学通讯中起着重要作用.有关这些次生物质的生物合成、代谢调控、生理功能以及与环境相互作用的研究近十多年来取得了重要进展.迄今为止,已经有3 0多种植物挥发性物质的合成酶基因被克隆.这些基因调控着植物萜类、芳香化合物、脂肪酸衍生物这三大类主要挥发性物质的生物合成.由于潜在的应用价值,近几年该领域颇受注目,特别是应用基因工程技术设计植物释放特殊气味物质,诸如特定的驱避剂或者其它控制植物或昆虫行为的特殊气味乃至与人类健康相关的药用气味物质.该文就植物挥发性物质的生物合成、生理和生态功能以及基因工程方面的研究进展作一概述.     

人参植物皂苷生物合成相关新基因的筛选与鉴定

人参植物根进行的特定发育过程在药用次生物———人参皂苷生物合成和累积中发挥重要作用。为从人参根中分离出人参皂苷生物合成相关基因 ,采用抑制差减杂交技术 ,构建四年和一年生人参根组织mRNA群体间正向差减cDNA文库。对从差减文库中筛选的 4 0个阳性cDNA克隆进行酶切、PCR与逆向Northern斑点杂交鉴定、DNA测序以及核苷酸序列同源性比较。结果表明 ,获得的 6个差减克隆在GenBank/DDBJ/BMBL无对应的同源基因 ,代表新基因序列。与此同时 ,使用Northern印迹杂交验证及半定量RT PCR进一步确认 ,6个转录本为根发育阶段差异性表达基因。因而提示 ,它们可能在人参皂苷生物合成中发挥了重要作用。此外 ,在人参茎、叶与种子中亦能检测到上述基因转录本的表达。目前 ,6个新基因已被命名 ,在GenBank注册并获登录号 ,为克隆上述新基因cDNA全长序列及深入鉴定其在人参皂苷生物合成中的功能提供了重要实验依据。     

植物花青素苷生物合成及调控的研究进展

花青素苷( anthocyanin)是植物新陈代谢过程中产生的类黄酮物质,决定被子植物花、果实、种皮、茎、叶和根等的颜色,具有重要的营养价值和药理作用.近年来关于花青素生物合成途径的研究已取得突破,综述了植物花青素苷基因研究现状和发展趋势,包括植物花青素生物合成途径、参与生物合成途径中相关的结构基因和调控基因及功能研究以及影响花青素苷生物合成的环境因素等的研究进展.     

MicroRNA与药用植物

MicroRNA（miRNA）是一类长度约为19～25个核苷酸的内源性非编码小分子单链RNA,对植物生长发育、次生代谢产物的生物合成以及抗逆性等有重要作用.近年来关于植物中miRNA的研究进展异常迅速,尤其是药用植物,目前已从一些药用植物中鉴定出miRNA,并分析了其在药用植物中的调控作用,这对药用植物的研究具有重要意义.本文综述了miRNA在植物中的产生途径、作用机制,同时重点介绍了miRNA在药用植物中的研究情况,使人们对药用植物中miRNA有更深的认识,为药用植物研究拓展新思路.     

高等植物叶绿素生物合成的研究进展

叶绿素是植物叶绿体内参与光合作用的重要色素,其功能是捕获光能并驱动电子转移到反应中心.整个叶绿素生物合成过程(L-谷氨酰-tRNA→叶绿素a→叶绿素b)需要15步反应,涉及15种酶,迄今在模式植物拟南芥中已分离到27个编码这些酶的基因,完成了以拟南芥为代表的被子植物叶绿素生物合成全部基因的克隆.本文主要对近年来国内外有关植物叶绿素的生物合成过程及相关酶基因的克隆、生物合成途径中2个关键步骤(σ-氨基酮戊酸(ALA)合成和Mg离子插入原卟啉Ⅸ的调节)、影响叶绿素生物合成的主要因素(光、温度、营养元素等),以及叶绿素生物合成相关酶的其他生物学功能等的研究进展进行综述.     

细胞分裂素生物合成基因转化植物的研究进展

植物激素是调节植物生长发育的微量生理活动物质,其中细胞分裂江是一类较活跃的植物激素,它几乎在植物发育的所有阶段都起作用,因此对细胞分裂江的生理作用及其机理的研究,具有十分重要的理论及应用价值。从根瘤农杆菌中鉴定和克臣细胞分裂素生物合成基因的成功以及植物转基因技术的建立,使人们可以采用基因工程的途径研究细胞分裂素的生理作用,为定向控制作物的生长发育提供了可能,同时也为应用植物激素进行遗传育种展示了广阔的前红．1细胞分裂素生物合成基因高等植物体中与细胞分裂江生物合成有关的基因还未被克隆出来,但目前已…     

植物花青素合成途径中的调控基因研究进展

花青素广泛分布于高等植物中,是一种水溶性的植物色素,与农作物的多种品质性状密切相关。虽长期受到关注,但其生物合成途径则是近年来随着拟南芥等植物突变体研究的深入才取得突破的。对于花、果实和种子中的花青素研究始终是热点,近来国内外有很多关于花青素合成与基因调控发明研究的报道。随着研究的深入不仅可以为医疗保健等提供科学依据,而且有助于其在农业生产中应用。本文综述了植物花青素基因的研究现状和发展趋势,包括植物花青素生物合成途径,生物合成途径中相关转录因子的调控,以及已经分离和克隆的调控基因在功能方面的研究进展。     

植物细胞色素P450

对植物细胞色素P450(CYP450)基因的分离,植物CYP450在苯丙烷类物质、芥子油苷及IAA和萜类等物质的生物合成中的功能,以及对天然生物合成与人工合成物质的解毒功能等研究进展作了简要的综述。指出分离植物细胞色素P450基因,并对其生物学功能进行分析以及植物细胞色素P450降解除草剂的机制及其在环境生物修复等方面的应用是今后一段时间内植物CYP450领域的研究热点。     

An ethnobotanical survey of indigenous knowledge on medicinal plants used by the traditional healers of the Lwamondo area,Limpopo province,South Africa

The use of medicinal plants in the treatment and prevention of diseases is attracting the attention of scientists worldwide. Approximately 3000 plant species are currently used by an estimated 200,000 indigenous traditional healers in South Africa. The specific part of the plant used for medicinal applications varies from species to species, and from one traditional healer to another. This study was carried out to explore and record those plants and plant parts used for treating various human ailments by the traditional healers of the Lwamondo area in the Limpopo province, South Africa for medicinal purposes. Ethnobotanical data were collected from 30 traditional healers (24 females and 6 males) in the Lwamondo area of Venda, by means of a data capture questionnaire focusing on the local names of the medicinal plants, their medicinal uses, the plant parts used, and methods of preparation and of administering treatments to patients. The survey identified 16 medicinal plants from 7 families, with 14 genera, used to treat a range of ailments in the Lwamondo area. The Fabaceae family was the most commonly used plant family representing 43.8% of all the medicinal plants species recorded by this study, followed by the Varbenaceae family at 18.8%. The plant parts most frequently used were the roots (44.5%), followed by the leaves (25.9%), bark (14.8%), the whole plant (11%), and flowers (3.7%). Most of the traditional healers obtained their extracts by boiling the medicinal plants. The most often recurring ailment treated by healers was stomach problems, using 31.3% of all the medicinal plants reported in this study for preparing such treatments. The following medicinal plants were covered by this study: Annona senegalensis, Schkuhria pinnata, Diospyros mespiliformis, Piliostigma thonningii, Senna obtusifolia, Bauhinia galpinii. The rural communities of the Lwamondo area possess a wealth of information on medicinal plants and their applications. This ethnobotanical survey can help scientists identify for further research those plants whose medicinal properties may be useful in the development of new drugs.     

无量山国家级自然保护区药用维管植物资源多样性研究

以景东无量山国家级自然保护区为对象,通过样地调查、标本鉴定和查阅资料,对保护区内药用维管植物的种类和生存状况进行研究。结果显示,保护区内药用维管植物共有80科168属218种,占该区维管植物总数的57.37%。药用维管植物生长型分析表明,草本植物占绝对优势。药用部位分析表明,以根和全草入药是其主要利用形式。对药用维管植物的功效分析显示,该地区以清热类、活血化淤类和祛风湿类药物为主。对保护区内药用维管植物濒危等级的评估显示,无危种类占总数的82.11%,说明保护状况良好。保护区不同功能区内维管植物物种丰富度为:核心区缓冲区实验区,其中药用维管植物所占的比例为:核心区缓冲区实验区。对不同功能区药用维管植物相似性分析结果表明,核心区和实验区物种为极不相似;核心区和缓冲区物种为轻度相似。本研究表明保护区的建立对药用植物多样性保护起到了重要作用,明确了保护区药用维管植物的种类及生存状况,为进一步开展药用植物资源的保护和利用研究提供了参考。     

MADS-BOX GENES: DEVELOPMENT AND EVOLUTION OF PLANT BODY PLANS

We review functional data on MADS-box genes, recent phylogenetic analyses of these coding regions, and their roles in the development and evolution of key morphological innovations in plants. We map the origin of important morphological structures in particular diverse stages of the life cycle in different plant clades onto organismal phylogenies, and present relevant molecular genetic aspects of development related to the MADS-box genes. We focus on reproductive structures of the sporophyte because most functional characterizations have been done of MADS-box genes involved in flower development. We discuss MADS-box evolution in flowering plants, but we also review studies in the other nonflowering vascular plants, gymnosperms (conifers and gnetales), and ferns and preliminary data from the algae. We suggest that floral (e.g. flowering time, inflorescence, and flower meristem identity) MADS-box and nonfloral plant MADS-box genes should be the focus of future comparative research. Cloning and functional analyses of MADS-box genes in bryophytes, particularly in the experimental system Physcomitrella patens (Hedw.) B.S.G., are needed. The ABC model of floral organ specification is an excellent general representation of an important network of genes; however, formal analytical tools are required to integrate data on complex gene interaction in comparative analyses. This and other analytical approaches to constructing gene network models will help to frame homology hypotheses in an evolutionary and developmental framework.     

广西恭城瑶族集市药用植物的民族植物学调查

采用民族植物学的研究方法和手段,对恭城瑶族境内周期性集市药用植物及相关的传统知识进行了调查。主要研究结果如下：恭城瑶族民众与野生药用植物的关系极为密切,研究地区集市中常见药用植物71种,均为野生植物,常用于治疗肠胃、呼吸道、感染、风湿和外伤等疾病。在调查地区的野生药用植物资源及相关的传统知识面临着新的威胁,亟待采取必要的措施予以保护。     

Ethnobotanical Survey of Medicinal Plants at Periodic Markets of Autonomous County of Gongcheng Yao in Guangxi

Gongcheng is the second largest county in Guangxi with about 163000 Yao population. Periodic Markets are important places for trading of medicinal plants harvested by Gongcheng Yao villagers. The study aimed to look into the marked traded medicinal plants that are used by local people for curing various ailments. Ethnobotanical market survey methods, interviews, Participatory Action Research (PAR) and field visits were planned to elicit information on the uses of various medicinal plants. It was found that 71 plant species in the market which belong to 41 families are commonly used by local people for curing various diseases, all species are wild plants. A total of 133 records of medical uses in 52 herbal recipes for the treatment some common diseases. In most of the recipes recorded, digestion diseases, respiratory system diseases, infectious diseases,rheumatological diseases and surgery are used. The traditional knowledge about the number of medicinal plants available in that area and used by interviewees was positively correlated with the threats on medicinal plants in the wild habitats of the research area, which indicating that the diversity of wild medicinal plants and the associated traditional knowledge trends to disappear in the area.     

Culturable Endophytes of Medicinal Plants and the Genetic Basis for Their Bioactivity

The bioactive compounds of medicinal plants are products of the plant itself or of endophytes living inside the plant. Endophytes isolated from eight different anticancer plants collected in Yunnan, China, were characterized by diverse 16S and 18S rRNA gene phylogenies. A functional gene-based molecular screening strategy was used to target nonribosomal peptide synthetase (NRPS) and type I polyketide synthase (PKS) genes in endophytes. Bioinformatic analysis of these biosynthetic pathways facilitated inference of the potential bioactivity of endophyte natural products, suggesting that the isolated endophytes are capable of producing a plethora of secondary metabolites. All of the endophyte culture broth extracts demonstrated antiproliferative effects in at least one test assay, either cytotoxic, antibacterial or antifungal. From the perspective of natural product discovery, this study confirms the potential for endophytes from medicinal plants to produce anticancer, antibacterial and antifungal compounds. In addition, PKS and NRPS gene screening is a valuable method for screening isolates of biosynthetic potential.     

Investigation of the biosynthetic potential of endophytes in traditional Chinese anticancer herbs

Traditional Chinese medicine encompasses a rich empirical knowledge of the use of plants for the treatment of disease. In addition, the microorganisms associated with medicinal plants are also of interest as the producers of the compounds responsible for the observed plant bioactivity. The present study has pioneered the use of genetic screening to assess the potential of endophytes to synthesize bioactive compounds, as indicated by the presence of non-ribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) genes. The total DNA extracts of 30 traditional Chinese herbs, were screened for functional genes involved in the biosynthesis of bioactive compounds. The four PCR screens were successful in targeting four bacterial PKS, six bacterial NRPS, ten fungal PKS and three fungal NRPS gene fragments. Analysis of the detected endophyte gene fragments afforded consideration of the possible bioactivity of the natural products produced by endophytes in medicinal herbs. This investigation describes a rapid method for the initial screening of medicinal herbs and has highlighted a subset of those plants that host endophytes with biosynthetic potential. These selected plants can be the focus of more comprehensive endophyte isolation and natural product studies.     

An ethnobotanical study of medicinal plants used by local people in the lowlands of Konta Special Woreda, southern nations, nationalities and peoples regional state, Ethiopia

Background

Research was carried out in Konta Special Woreda (District); it is a remote area with lack of infrastructure like road to make any research activities in the area. Therefore, this research was conducted to investigate medicinal plants of the Konta people and to document the local knowledge before environmental and cultural changes deplete the resources.

Methods

The information was collected between October 2006 and February 2007. Interview-based field study constituted the main data collection method in which the gathering, preparation, use, previous and current status and cultivation practices were systematically investigated. The abundance, taxonomic diversity and distribution of medicinal plants were studied using ecological approach.

Results

A total of 120 species, grouped within 100 genera and 47 families that are used in traditional medical practices were identified and studied. The Fabaceae and Lamiaceae were the most commonly reported medicinal plants with 16 (13.3%) and 14 (12%) species, respectively. 25.4% of the total medicinal plants are collected from homegardens and the rest (74.6%) are collected from wild habitats. Of the total number of medicinal plants, 108 species (90%) were used to treat human ailments, 6 (5%) for livestock diseases and the remaining 6 (5%) were used to treat both human and livestock health problems. The major threats to medicinal plants reported include harvesting medicinal plants for firewood (24.8%) followed by fire (22.3%) and construction (19%). Of the four plant communities identified in the wild, more medicinal plant species (34) were found in community type-4 (Hyparrhenia cymbaria-Erythrina abyssinica community), which accounted for 61.8%.

Conclusion

Konta Special Woreda is an important area for medicinal plants and associated local knowledge; the natural vegetation being the most important reservoir for the majority of the medicinal plants. Environmental and cultural changes are in the process of threatening the resources and this signals the need for serious efforts to create public awareness so that measures are taken to conserve the medicinal plants in the natural ecosystems and other suitable environments.     

基于专利分析的转基因药用植物技术发展趋势研究

据世界卫生组织不完全统计,药用植物在发展中国家和发达国家的使用量均逐年上升。随着对药用植物需求和消耗的不断增加,许多药用植物资源急剧减少。面对日趋严峻的药用植物资源,利用转基因技术进行品种改良,提高其有效成分含量成为研究的重要方向之一。基于德温特数据库的专利信息,对收录的有关转基因药用植物领域的专利文献进行统计分析,分别从全球和中国本土两个层面对转基因药用植物的研究现状、核心技术、研究热点、技术分布与格局等方面进行研究。结果表明,在转基因药用植物领域美国技术实力最强,而中国专利数量名列前茅,但其国际影响力尚且不足。研究结果为相关企业和科研机构掌握转基因药用植物的发展趋势提供必要的情报支持。