Making small molecules in plants: A chassis for synthetic biology-based production of plant natural products

Plant natural products have been extensively exploited in food,medicine,flavor,cosmetic,renewable fuel,and other industrial sectors.Synthetic biology has recently emerged as a promising means for the cost-effective and sustainable production of natural products.Compared with engineering microbes for the production of plant natural products,the potential of plants as chassis for producing these compounds is underestimated,largely due to challenges encountered in engineering plants.Knowledge in pl...     

Evolution and current status of ecological phytochemistry

Phytochemical studies have experienced a great deal of change during the last century, not only regarding the number of compounds described, but also in the concept of phytochemistry itself. This change has mainly been related to two key points: the methodologies used in phytochemical studies and the questions regarding 'why secondary metabolites appeared in plants and in other living organisms?' and 'what is their role?'. This transformation in the field has led to new questions concerning such different subjects as evolution, paleobotany, biochemistry, plant physiology and ethnography. However, the main issue is to clarify the role that secondary metabolites play in the plant (and other organisms) and whether the resources invested in their production (C and N allocation, genes encoding their biogenetic pathways, specific enzymes, energy-rich molecules such as ATP and NADPH) have or lack a reasonable reward in terms of advantages for survival. Consequently, in this review the main emphasis will be placed on two subjects related to the evolution of phytochemical studies. The first aim is to describe briefly the influence that the development of the methodologies needed for compound isolation and structure elucidation have had on the field of phytochemistry. The second area to be covered concerns the new theories addressing the role of secondary metabolites from an ecological point of view: co-evolution of plants and their potential enemies (phytophagous insects, microbes, herbivores and other plants), chemical plant defence, adaptative strategies of phytophagues to plant toxins (among them sequestration will be briefly mentioned), and models and theories for carbon and nitrogen allocation. Some final remarks are made to summarize our opinion about the immediate future of phytochemical ecology and phytochemical studies.     

From waste products to ecochemicals: fifty years research of plant secondary metabolism

The isolation of morphine ('principium somniferum') by Friedrich Wilhelm Sertürner about 200 years ago is generally accepted as the beginning of scientific phytochemistry (plant secondary products research). For about 150 years this research addressed almost exclusively the isolation and structure elucidation of new plant products. It had great impact on the development of modern organic chemistry and pharmaceutical industry and provided the chemical basis for biological research on plant secondary metabolism, which began about 50 years ago. The historical development of this field to its present state of knowledge will be considered in this review from three angles of vision: mechanistic, functional and evolutionary perspectives. Mechanistic research started on the metabolite level and was initiated by the availability of radioactive nuclides in the early 1950s. By means of sophisticated tracer techniques, the biosynthetic routs of most secondary pathways were outlined and provided the basis for the enzymatic characterization of biosynthetic pathways in the 1970s and 1980s, followed by the identification of the corresponding genes beginning in the late 1980s. During this 50-year period of intensive research a change of paradigm occurred addressing the question: why do plants synthesize this immense rich diversity of secondary metabolites comprising more than 200,000 structures? For a long time regarded as waste products or assigned with various other attributes their indispensable role as components of the survival strategy of plants in a mostly hostile environment appears now generally accepted. Along with the great progress in the field of chemical ecology, the emerging field of molecular evolution provided crucial evidence that during evolution of secondary metabolism genes encoding enzymes of plant's primary metabolism were duplicated, recruited and diversified for new functions under the everlasting and continuously changing selection pressure of the environment.     

Phytochemical investigation of the leaves of Leptoderris fasciculata

Leptoderris fasciculata (Benth.) Dunn is a woody liana that grows in the tropical zone of West Africa, where it is exploited in traditional medicine for a number of uses. In the south-eastern Ivory Coast, it is applied to stop bleeding in women after childbirth or in cases of menorrhagia. The phytochemistry of this plant has received little previous attention. We report the isolation of 4′,5,6,7-tetramethoxyisoflavone and dihydrochalcone, new as natural products, together with 10 known compounds from the leaves of L. fasciculata collected in the Ivory Coast.     

The Delphic bee: Bees and toxic honeys as pointers to psychoactive and other medicinal plants

Herein a brief review, with 49 references, of the history and phytochemistry of toxic honeys, in which bees have sequestered plant secondary compounds naturally occurring in plant nectars (floral and extrafloral). It is hypothesized that such toxic honeys could have served as pointers to psychoactive and other medicinal plants for human beings exploring novel ecosystems, causing such plants to stand out, even against a background of extreme biodiversity. After reviewing various ethnomedicinal uses of toxic honeys, the author suggests that pre-Columbian Yucatecan Mayans intentionally produced a psychoactive honey from the shamanic inebriant Turbina corymbosa as a visionary substrate for manufacture of their ritual metheglin, balché.     

Medicinal history of North American Veratrum

Plants belonging to the genus Veratrum have been used throughout history for their medicinal properties. During the nineteenth and twentieth centuries, phytochemical investigations revealed a host of steroidal alkaloids in Veratrum species, some of which are potent bioactives. This review discusses Veratrum species that grow in North America with a focus on the medicinal history of these plants and the steroidal alkaloids they contain. While significant reviews have been devoted to singularly describing the plant species within the genus Veratrum (botany), the staggering breadth of alkaloids isolated from these and related plants (phytochemistry), and the intricacies of how the various alkaloids act on their biological targets (physiology and biochemistry), this review will straddle the margins of the aforementioned disciplines in an attempt to provide a unified, coherent picture of the Veratrum plants of North America and the medicinal uses of their bioactive steroidal alkaloids.     

流式细胞术的发展及在植物研究中的应用

流式细胞术是通过对液流中各种荧光标记的颗粒进行多参数快速高效的定性或定量测定的方法,在科学研究的多个领域发挥重要作用。然而,由于植物组织及细胞壁和次生代谢产物等细胞的特殊成分和结构,限制了其在植物研究领域的应用。本文在介绍流式细胞仪发展和组成分类的基础上,着重讨论了流式细胞术在植物领域的应用、研究进展及应用限制,进而展望该研究领域的发展趋势,为拓宽植物流式细胞术的潜在应用范围提供新的思考方向。     

基因芯片技术在拟南芥研究中的应用

基因芯片是研究生物大分子功能的新技术,目前此技术已经广泛地应用到植物研究中。拟南芥是植物分子生物学领域的模式植物,通过对其基因结构及功能的详尽研究,可以更好地理解和认识遗传上更为复杂的高等植物的生长和发育过程。本综述了基因芯片在模式植物拟南芥研究中的应用。     

植物气味腺研究进展

气味腺是花器官上能够产生和释放花气味的特殊腺体结构,在传粉过程中与其他花部性状结合能够吸引传粉者访花,气味腺的研究有助于揭示动物与植物之间的协同进化机制,此外,气味腺外部形态特征及细胞微形态可作为分类依据之一。对气味腺的结构、类型和检测方法,及其在植物科属中的分布情况进行了归纳总结,并对气味腺在传粉过程中和分类学上的意义进行了分析。最后提出只有结合分子实验技术手段,全面综合考虑繁殖生物学和植物化学的分析方法,才能深入理解气味腺的多样性与演化。     

Evolution in invasive plants: implications for biological control

Evidence is increasing that invasive plants can undergo rapid adaptive evolution during the process of range expansion. Here, we argue that evolutionary change during invasions will also affect plant-antagonist interactions and, thus, will have important implications for biological control programmes targeted at invasive plants. We explore how altered selection in the new range might influence the evolution of plant defence (resistance and tolerance) and life history. The degree to which such evolutionary processes might affect biological control efficacy is largely unexplored. We hope that, by testing the hypotheses that we propose here, a closer link can be established between biological control and evolutionary biology, to the benefit of both disciplines.     

植物提取物微生物限量标准及检测技术进展

植物提取物的微生物检测是保证植物产品安全性的重要手段,制定严格的植物提取物质量控制标准体系,特别是功能性食品、食品添加剂和植物源日用化学品等产品中微生物的检测和控制,对产品的质量及安全保证具有重要作用,是影响植物提取业实现全面发展的关键问题.本文主要介绍了部分国家植物提取物的微生物限量标准和植物提取物微生物检测的国内外现状与发展趋势,并就如何建立植物提取物微生物检测行业标准体系提出了若干建议.希望对我国植物提取业实现新时期跨越式发展提供参考.     

RNA沉默与植物病毒

植物中RNA沉默（RNAsilencing)亦称为转录后基因沉默（PTGS）或共抑制,是植物抵抗外来核酸（转座子、转基因或病毒）入侵,并保护自身基因组完整性的一种防御机制。RNA沉默是近十年来发现的植物界中普遍存在的现象,已成为植物分子生物学领域的一个新的研究方向。对RNA沉默特点和机制的研究表明,植物病毒与（转基因）植物内发生的RNA沉默有着密切的联系,作者从病毒对RNA沉默的诱导、抑制、防御等方面,简述了RNA沉默与病毒的关系。并对病毒载体所诱导的RNA沉默在植物发育和基因组功能分析等方面的应用价值进行了讨论。     

Impact of natural products in modern drug development

Usage of natural substances as therapeutic agents in modern medicine has sharply declined from the predominant position held in the early decades of last century, but search for bioactive molecules from nature (plants, animals, microflora) continues to play an important role in fashioning new medicinal agents. With the advent of modern techniques, instrumentation and automation in isolation and structural characterisation, we have on hand an enormous repository of natural compounds. In parallel to this, biology has also made tremendous progress in expanding its frontiers of knowledge. An interplay of these two disciplines constitutes the modern thrust in research in the realm of compounds elaborated by nature. The purpose of this article is to underline how natural products research continues to make significant contributions in the domain of discovery and development of new medicinal products. It is proposed to present the material under several heads, each of which has made natural products research relevant in the search for new and better medication.     

植物提取物微生物限量标准及检测技术进展

植物提取物的微生物检测是保证植物产品安全性的重要手段, 制定严格的植物提取物质量控制标准体系, 特别是功能性食品、食品添加剂和植物源日用化学品等产品中微生物的检测和控制, 对产品的质量及安全保证具有重要作用, 是影响植物提取业实现全面发展的关键问题。本文主要介绍了部分国家植物提取物的微生物限量标准和植物提取物微生物检测的国内外现状与发展趋势, 并就如何建立植物提取物微生物检测行业标准体系提出了若干建议。希望对我国植物提取业实现新时期跨越式发展提供参考。     

数字植物标本在科学研究中的应用: 进展及挑战

全球自然历史博物馆中保存着约3.9亿份植物标本,这些标本为科学研究提供了重要支撑。近20年来,随着标本数字化的发展,数字植物标本在科学研究中的应用日益广泛。数字植物标本不仅为标本传统的用途提供了便利,而且衍生出了新的研究主题和方向。鉴于目前中文文献中缺乏数字植物标本在科学研究中的应用概述及所面临挑战的分析,该文概述了全球植物标本数字化的现状,并对数字标本在生物地理学、入侵生物学、气候变化和保护生物学等领域中的应用情况进行了综述。主要集中在以下5个方面:(1)生物地理学研究中物种分布格局及其成因;(2)编制入侵植物名录、重建入侵历史和预测入侵风险;(3)气候变化情景下植物分布格局的变迁机制;(4)生物多样性编目和保护区规划;(5)其他相关应用(如农业和民族药物学等)。最后,针对数字植物标本应用中存在的问题进行了讨论,并提出了应对策略,同时提出开发将数字标本与其他学科大数据进行整合分析的新理论、新方法和新工具,为植物学及相关学科提供参考。     

Invasive plant suppresses the growth of native tree seedlings by disrupting belowground mutualisms

The impact of exotic species on native organisms is widely acknowledged, but poorly understood. Very few studies have empirically investigated how invading plants may alter delicate ecological interactions among resident species in the invaded range. We present novel evidence that antifungal phytochemistry of the invasive plant, Alliaria petiolata, a European invader of North American forests, suppresses native plant growth by disrupting mutualistic associations between native canopy tree seedlings and belowground arbuscular mycorrhizal fungi. Our results elucidate an indirect mechanism by which invasive plants can impact native flora, and may help explain how this plant successfully invades relatively undisturbed forest habitat.     

Agrobacterium tumefaciens as an agent of disease

Twenty-six years ago it was found that the common soil bacterium Agrobacterium tumefaciens is capable of extraordinary feats of interkingdom genetic transfer. Since this discovery, A. tumefaciens has served as a model system for the study of type IV bacterial secretory systems, horizontal gene transfer and bacterial-plant signal exchange. It has also been modified for controlled genetic transformation of plants, a core technology of plant molecular biology. These areas have often overshadowed its role as a serious, widespread phytopathogen - the primary driver of the first 80 years of Agrobacterium research. Now, the diverse areas of A. tumefaciens research are again converging because new discoveries in transformation biology and the use of A. tumefaciens vectors are allowing the development of novel, effective biotechnology-based strategies for the control of crown gall disease.     

EXPERIMENTAL PLANT REPRODUCTIVE BIOLOGY AND REPRODUCTIVE CELL MANIPULATION IN HIGHER PLANTS: NOW AND THE FUTURE

Experimental plant reproductive biology has recently emerged as a new form of experimental embryology characterized by the direct experimental isolation and manipulation of reproductive cells and protoplasts. This work is fostered by current multidisciplinary trends in the sciences and serves to deepen our knowledge about the control of reproductive processes by providing novel in vitro material. The techniques of experimental plant reproductive biology also show great potential in providing new means for biotechnology, leading to significant refinements in plant breeding in higher plants that may eventually permit direct reproductive cell engineering. Recent achievements by our research group in experimental manipulation and biological studies of pollen protoplasts, generative cells, sperm cells, and embryo sacs are reviewed, and some ideas about future developments in this new area are presented.     

Homology in comparative, molecular, and evolutionary developmental biology: the radiation of a concept

The present paper analyzes the use and understanding of the homology concept across different biological disciplines. It is argued that in its history, the homology concept underwent a sort of adaptive radiation. Once it migrated from comparative anatomy into new biological fields, the homology concept changed in accordance with the theoretical aims and interests of these disciplines. The paper gives a case study of the theoretical role that homology plays in comparative and evolutionary biology, in molecular biology, and in evolutionary developmental biology. It is shown that the concept or variant of homology preferred by a particular biological field is used to bring about items of biological knowledge that are characteristic for this field. A particular branch of biology uses its homology concept to pursue its specific theoretical goals.