The Discovery of Medicines from Plants: A Current Biological Perspective1

The Discovery of Medicines from Plants: A Current Biological Perspective. The last 50 years have seen tremendous innovations in the process of discovering novel bioactive compounds from plants. Every stage of the natural products discovery and development pipeline has seen major advances, so as a result, today it is possible to evaluate large numbers of plant extracts efficiently and in more effective ways against a wider array of disease targets. Despite all of these technological advances and numerous large-scale discovery efforts, the number of new drugs developed as natural products from plants to reach the market has been surprisingly low, very different from the continuing productive discovery work from microbes. The innovations in the discovery process are reviewed, possible explanations for low success of recent discovery efforts are explored, and an effort is made to estimate the future potential of plants as a discovery resource. It may be that the low rate of discovery during this developmental period of natural products discovery is a consequence of technological limitations of the discovery process rather than a lack of interesting compounds in plants, and that even when necessary assumptions are taken into account, conservative estimates would indicate great potential for the discovery of new drugs from plants.     

Psoriasis Therapy: A Current Perspective

Psoriasis is a common papulosquamous skin disease which frequently presents a therapeutic challenge to physicians. Topical therapy with steroids, coal tars and anthralin are effective when used properly for many patients. More severely affected patients may require phototherapy using coal tars and anthralin plus ultraviolet radiation. Systemic methotrexate administration is indicated for some patients with severe skin and arthropathic psoriasis. Treatment using psoralen and long-wavelength ultraviolet phototherapy has recently been approved and is effective in many patients, but long-term safety remains a question. Synthetic retinoids are experimental drugs currently being evaluated for severe forms of psoriasis.     

高价值的医药分子农业

植物转基因技术使传统农业逐渐向分子农业转型。农业的作用由原来的简单的提供衣、食、住扩展到为医药业、工业提供优质、低廉的原料或产品。医药分子农业作为分子农业的重要组成部分,已改变了传统农业的生产结构,并因其自身具有较高的经济价值而将给农业带来巨大的经济效益。     

植物磷营养高效的分子生物学研究进展

挖掘利用植物自身的磷高效营养遗传资源是农业可持续发展的关键.磷高效营养性状涉及根形态、根分泌物、膜与体内磷转运以及菌根等许多方面,表现为数量遗传性状及受多基因控制.近年来,许多高亲和磷转运子基因已被克隆,磷向地上部转运和磷吸收负反馈调节的控制基因也被发现,对于根系分泌有机酸和酸性磷酸酶的基因的控制也有了一定的了解,但目前对于根毛、排根、根构型以及菌根的营养学意义性状的分子生物学研究进展缓慢.     

植物磷营养高效的分子生物学研究进展

挖掘利用植物自身的磷高效营养遗传资源是农业可持续发展的关键。磷高效营养性状涉及根形态、根分泌物、膜与体内磷转运以及菌根等许多方面,表现为数量遗传性状及受多基因控制。近年来,许多高亲和磷转运子基因已被克隆, 磷向地上部转运和磷吸收负反馈调节的控制基因也被发现, 对于根系分泌有机酸和酸性磷酸酶的基因的控制也有了一定的了解, 但目前对于根毛、排根、根构型以及菌根的营养学意义性状的分子生物学研究进展缓慢。     

A Primer to Molecular Phylogenetic Analysis in Plants

Reconstructing a tree of life by inferring evolutionary history is an important focus of evolutionary biology. Phylogenetic reconstructions also provide useful information for a range of scientific disciplines such as botany, zoology, phylogeography, archaeology and biological anthropology. Until the development of protein and DNA sequencing techniques in the 1960s and 1970s, phylogenetic reconstructions were based on fossil records and comparative morphological/physiological analyses. Since then, progress in molecular phylogenetics has compensated for some of the shortcomings of phenotype-based comparisons. Comparisons at the molecular level increase the accuracy of phylogenetic inference because there is no environmental influence on DNA/peptide sequences and evaluation of sequence similarity is not subjective. While the number of morphological/physiological characters that are sufficiently conserved for phylogenetic inference is limited, molecular data provide a large number of datapoints and enable comparisons from diverse taxa. Over the last 20 years, developments in molecular phylogenetics have greatly contributed to our understanding of plant evolutionary relationships. Regions in the plant nuclear and organellar genomes that are optimal for phylogenetic inference have been determined and recent advances in DNA sequencing techniques have enabled comparisons at the whole genome level. Sequences from the nuclear and organellar genomes of thousands of plant species are readily available in public databases, enabling researchers without access to molecular biology tools to investigate phylogenetic relationships by sequence comparisons using the appropriate nucleotide substitution models and tree building algorithms. In the present review, the statistical models and algorithms used to reconstruct phylogenetic trees are introduced and advances in the exploration and utilization of plant genomes for molecular phylogenetic analyses are discussed.     

展望即到来的“分子农业”

在过去20余年里,植物生物技术领域中最值得重视的是多种转基因植物的建成,并已在一些国家大面积种植,转基因植物另一方面的进展是合成有医疗价值的多肽、蛋白质、包括抗体、抗体表位、复杂蛋白质等。这里主要介绍转基因植物生产的医疗用多肽、蛋白质,特别是作为口服疫苗在动物和临床试验的成功,预示这种新的用药途径将对第三世界人民的健康起到重大作用。由于转基因口服疫苗不需通过常规发展反应器,仅仅依赖于农业,因此有人提出“分子农业”一词,以显示其优越性。     

展望即将到来的“分子农业”

在过去20余年里,植物生物技术领域中最值得重视的是多种转基因植物的建成,并已在一些国家大面积种植。转基因植物另一方面的进展是合成有医疗价值的多肽、蛋白质、包括抗体、抗体表位、复杂蛋白质等。这里主要介绍转基因植物生产的医疗用多肽、蛋白质,特别是作为口服疫苗在动物和临床试验的成功,预示这种新的用药途径将对第三世界人民的健康起到重大作用。由于转基因口服疫苗不需通过常规发酵反应器,仅仅依赖于农业,因此有人提出“分子农业”一词,以显示其优越性。     

Orbicules in Flowering Plants: A Phylogenetic Perspective on their Form and Function

Next to pollen, stamens of flowering plants often produce microstructures, called orbicules, lining the locules. Although the existence of orbicules has been known since 1865, their function still remains enigmatic. This paper surveys orbicule distribution throughout angiosperms, including +1,500 entries. We show that orbicules are found all over of flowering plants with an evolutionary trend towards orbicule absence in more derived clades. Orbicules are common in the ANITA-grade and 85 % of the monocots studied produce orbicules, with Orchidaceae, Commelinales and Zingiberales as notable exceptions. Within eudicots, asterids are most densely sampled with 61 % orbicule presence. Asteraceae and the majority of Lamiaceae lack orbicules. For 17 angiosperm orders orbicule distribution data are lacking entirely. We demonstrate that the hypothesized correlation of orbicule presence with non-amoeboid tapetum types holds true. The presence of orbicules is therefore a convenient proxy for tapetum characterization. The potential of orbicules as an a-cellular model system for patterned sporopollenin polymerization is discussed and suitable model plants for future functional orbicule-research are identified.     

Alligators and Endocrine Disrupting Contaminants: A Current Perspective

Many xenobiotic compounds introduced into the environment byhuman activity have been shown to adversely affect wildlife.Reproductive disorders in wildlife include altered fertility,reduced viability of offspring, impaired hormone secretion oractivity and modified reproductive anatomy. It has been hypothesizedthat many of these alterations in reproductive function aredue to the endocrine disruptive effects of various environmentalcontaminants. The endocrine system exhibits an organizationaleffect on the developing embryo. Thus, a disruption of the normalhormonal signals can permanently modify the organization andfuture function of the reproductive system. We have examinedthe reproductive and developmental endocrinology of severalpopulations of American alligator (Alligator mississippiensis)living in contaminated and reference lakes and used this speciesas a sentinel species in field studies. We have observed thatneonatal and juvenile alligators living in pesticide-contaminatedlakes have altered plasma hormone concentrations, reproductivetract anatomy and hepatic functioning. Experimental studiesexposing developing embryos to various persistent and nonpersistentpesticides, have produced alterations in gonadal steroidogenesis,secondary sex characteristics and gonadal anatomy. These experimentalstudies have begun to provide the causal relationships betweenembryonic pesticide exposure and reproductive abnormalitiesthat have been lacking in pure field studies of wild populations.An understanding of the developmental consequences of endocrinedisruption in wildlife can lead to new indicators of exposureand a better understanding of the most sensitive life stagesand the consequences of exposure during these periods.     

药用植物分子农场研究进展

植物分子农场可以利用植物生产具有药物用途的重组蛋白或者次生代谢化合物,应用广泛。随着对动植物中具有药物用途的代谢途径的深入解析,代谢途径中关键限速酶或调控蛋白的功能不断被明确,如何选择植物分子农场的底盘植物和遗传改造途径等问题,特别是如何协同提高植物制药产量与品质一直是植物分子农场体系建立中面临的关键科学问题。综述了药用的植物分子农场的最新研究进展,着重介绍了底盘植物的选择与药用植物分子农场的构建策略,以期为提高分子农场应用效果提供有力的科技支撑。     

Transgenic Plants for Insect Pest Control: A Forward Looking Scientific Perspective

One of the first successes of plant biotechnology has been the creation and commercialisation of transgenic crops exhibiting resistance to major insect pests. First generation products encompassed plants with single insecticidal Bt genes with resistance against major pests of corn and cotton. Modelling studies predicted that usefulness of these resistant plants would be short-lived, as a result of the ability of insects to develop resistance against single insecticidal gene products. However, despite such dire predictions no such collapse has taken place and the acreage of transgenic insect resistance crops has been increasing at a steady rate over the 9 years since the deployment of the first transgenic insect resistant plant. However, in order to assure durability and sustainability of resistance, novel strategies have been contemplated and are being developed. This perspective addresses a number of potentially useful strategies to assure the longevity of second and third generation insect resistant plants.     

分子医药农业研究进展

分子医药农业是利用转基因植物为载体,以农业生产的方式规模化生产各种有治疗用途的重组蛋白质及多肽。近20年来,随着植物生物反应器技术的多元化发展以及日趋成熟,植物分子医药农业产业悄然而生。近几年,一些分子医药农业生产的植物源医药产品已实现规模化生产,并进入市场。文中结合国内外最新的研究进展,重点对几种主要植物生物反应器的研究、产品的规模化生产以及产业化进程进行了阐述,以期为我国分子医药农业领域的研究与应用提供参考。     

分子医药农业研究进展

分子医药农业是利用转基因植物为载体,以农业生产的方式规模化生产各种有治疗用途的重组蛋白质及多肽。近20年来,随着植物生物反应器技术的多元化发展以及日趋成熟,植物分子医药农业产业悄然而生。近几年,一些分子医药农业生产的植物源医药产品已实现规模化生产,并进入市场。文中结合国内外最新的研究进展,重点对几种主要植物生物反应器的研究、产品的规模化生产以及产业化进程进行了阐述,以期为我国分子医药农业领域的研究与应用提供参考。