植物细胞悬浮培养中次生代谢产物积累的研究进展

我国是植物资源最丰富的国家之一。植物的活性成分主要为其次生代谢产物,并大多依赖于天然植物资源中直接提取获得。但由于自然环境的破坏、植物资源的过度开发及其栽培困难等原因,许多天然植物资源正在以惊人的速度消失。为了既能满足社会对植物次生代谢物的需求,又能合理开发利用自然植物资源和保护生态环境,悬浮细胞培养技术为生产药用植物活性成分提供了一条全新途径。但受目的产物含量低的限制,能用悬浮细胞培养技术生产的天然活性物质种类也十分有限。因此,进一步研究植物悬浮细胞培养合成活性成分的高产调控技术具有重要的意义。本文综述了近年来国内外应用悬浮细胞培养技术生产次生代谢产物及调控因素研究进展。     

植物次生代谢,离体培养条件下次生代谢生物积累及其调控研究进展

简述了高等植珠的几大类次生代谢产物及其合成途径,采用了大量研究实例以说明运用细胞工程生产代谢物的可能性,指出提高植物培养细胞中次生代谢物产量的各种调控途径。     

丹参代谢途径关键酶和次生代谢产物的研究进展

丹参次生代谢物是丹参入药的主要成分，文章从丹参次生代谢物的主要类型、合成途径、关键酶及培养环境的变化对丹参次生代谢物的影响等方面，综述了近年来国内外对丹参次生代谢产物积累的研究进展，论述了植物次生代谢主要合成途径中关键酶与代谢物积累的相关作用，列举了环境变化、诱导作用对丹参次生代谢物含量变化的影响，旨在为丹参的规范化种植和质量控制提供理论依据。     

虫害诱导植物合成防御性次生代谢产物的研究进展

昆虫对植物的取食活动可以激活植物的防御反应,诱导植物通过调控自身的代谢网络合成防御性次生代谢产物,抵御外界不良刺激。虫害诱导植物合成防御性次生代谢产物及其机制研究已成为近年来的研究热点之一。现对虫害诱导的植物防御性次生代谢产物、昆虫危害产生的各类激发子、植物对激发子的识别、虫害应答相关的信号转导通路及其对次生代谢物质积累的调控进行了综述,可为虫害诱导植物合成防御性次生代谢产物的机制研究提供参考,为植物虫害防治研究、植物次生代谢物质的生产和利用提供理论依据。     

诱导子对植物细胞培养中次生代谢物的调控机制

诱导子被认为是提高植物细胞培养中次生代谢产物最有效的途径之一.目前,对诱导子的研究以及所产生的次生代谢物的调控机制的研究越来越受到重视,本文就植物细胞在受诱导子作用后,产生的一系列生理生化事件进行讨论.     

植物次生代谢物途径及其研究进展

植物次生代谢是植物在长期进化过程中与环境相互作用的结果,由初生代谢派生。萜类、生物碱类、苯丙烷类为植物次生代谢物的主要类型,其代谢途径多以代谢频道形式存在,具有种属、生长发育期等特异性。从植物次生代谢物的分类、代谢途径及代谢调控基因工程等方面展开论述,重点介绍了次生代谢物的生物合成途径,以及利用基因工程等技术对植物次生代谢途径进行遗传改良等方面的研究进展,为全面认识植物代谢网络、合理定位次生代谢及其关键酶、促进野生植物资源可持续利用等提供理论依据。     

几种重要植物次生代谢防御反应物质的生物合成途径及分子调控机制研究进展

参与植物防御反应相关的次生代谢产物主要有酚类、萜类和生物碱类.近几年,随着转录组学、蛋白组学及新的分子生物学技术的广泛应用,极大地推进了植物次生代谢防御反应物质调控机制的研究进展.我们从这几类次生代谢物质的合成途径及其参与植物防御反应的分子调控机制两大方面进行概述,重点介绍这三类具有防御作用的次生代谢产物的生物合成途径、参与介导植物防御反应的相关信号分子及其转录调控机制,为正确认识植物次生代谢防御反应提供理论据.     

植物次生代谢产物简介

阐述了植物次生代谢产物的基本概念、主要功能,主要类型和生成次生代谢产物的主要途径,最后简单介绍了植物细胞大规模培养法生产有用次生代谢产物的现状。     

植物次生代谢、离体培养条件下次生代谢物积累及其调控研究进展

简述了高等植物的几大类次生代谢产物及其合成途径,采用了大量研究实例以说明运用细胞工程生产代谢物的可能性,指出提高植物培养细胞中次生代谢物产量的各种调控途径,特别用研究实例来展示前体饲喂及诱导子添加对提高目的产物含量的显著效果。文末还对该科研领域存在的问题及未来研究重点进行了讨论。     

影响毛状根生长及其次生代谢产物合成因素的研究进展

利用发根农杆菌转化药用植物,并对毛状根进行离体培养,大量提取重要成分,是药用资源植物可持续发展的有效途径之一。讨论了毛状根的诱导、影响毛状根生长及次生代谢产物形成的因素、利用毛状根培养技术生产植物次生代谢物的最新研究进展。     

Eliciting secondary metabolism in plant cell cultures

Plant cell cultures are potentially rich sources of valuable pharmaceuticals and other biologically active phytochemicals, but relatively few cultures synthesize secondary compounds over extended periods in amounts comparable to those found in the whole plant. Frequently, no secondary metabolites characteristic of the intact plant are produced. So far, the manipulation of culture media, culture conditions and phytohormone levels have, in general, failed to permit commercial production of those phytochemicals useful in medicine and industry. This almost certainly reflects the lack of understanding of basic secondary metabolic regulation in cultured plant cells.

Microbial insult can induce antibiotic phytochemical synthesis in cultured plant cells: the microbial molecules which stimulate synthesis have been called ‘elicitors’. Increased synthesis of secondary products in response to elicitation of various types appear to be the general response of cultured cells. This paper illustrates the immense biotechnological potential of plant cell culture—‘elicitor’ (inducer) interactions to the large scale production of secondary metabolites, and suggests several lines of enquiry that remain to be authoritatively treated.     

Generation of Colors and Flavors in Plant Cell and Tissue Cultures

Plant cell and tissue cultures can be used for the synthesis and production of secondary metabolites like colors, flavors, and sweeteners. Most often, plant cell cultures fail to produce the desired products. In such cases strategies to improve the production of secondary metabolites must be considered.

Plant cell culture technology has now reached the point where a variety of culture types can be critically assessed as potential sources of existing and novel flavors and pigments. This brief review gives examples where progress has been made in the development of plant tissue culture systems.     

Influence of abiotic stress signals on secondary metabolites in plants

Plant secondary metabolites are unique sources for pharmaceuticals, food additives, flavors, and industrially important biochemicals. Accumulation of such metabolites often occurs in plants subjected to stresses including various elicitors or signal molecules. Secondary metabolites play a major role in the adaptation of plants to the environment and in overcoming stress conditions. Environmental factors viz. temperature, humidity, light intensity, the supply of water, minerals, and CO₂ influence the growth of a plant and secondary metabolite production. Drought, high salinity, and freezing temperatures are environmental conditions that cause adverse effects on the growth of plants and the productivity of crops. Plant cell culture technologies have been effective tools for both studying and producing plant secondary metabolites under in vitro conditions and for plant improvement. This brief review summarizes the influence of different abiotic factors include salt, drought, light, heavy metals, frost etc. on secondary metabolites in plants. The focus of the present review is the influence of abiotic factors on secondary metabolite production and some of important plant pharmaceuticals. Also, we describe the results of in vitro cultures and production of some important secondary metabolites obtained in our laboratory.     

肉苁蓉细胞悬浮培养的代谢动力学研究

通过研究肉苁蓉细胞悬浮培养过程中碳源、氮源、磷源的消耗,pH、电导率的变化,以及细胞的生长、胞内外蛋白质含量和次生代谢产物苯乙醇苷、总黄酮和多糖合成的情况,掌握了细胞生长、营养消耗与次生代谢产物积累的基本规律,为建立结构化动力学模型奠定了基础。     

Effect of aposymbiotic conditions on colony growth and secondary metabolite production in the lichen-forming fungus Ramalina dilacerata

The production of secondary metabolites by aposymbiotic lichen-forming fungi in culture is thought to be influenced by environmental conditions. The effects of the environment may be studied by culturing fungi under defined growing parameters to provide a better understanding of the role of the large number of polyketide synthase (PKS) gene paralogs detected in the genomes of many fungi. The objectives of this study were to examine the effects of culture conditions (media composition and pH level) on the colony growth, the numbers of secondary products, and the expression of two PKS genes by the lichen-forming fungus Ramalina dilacerata. Four types of growth media at four different pH levels were prepared to culture spore isolates of R. dilacerata. Colony diameter and texture were recorded. The number of secondary compounds were determined by thin layer chromatography (TLC) and high performance liquid chromatography (HPLC). Expression of two PKS genes (non-reducing (NR) and 6-MSAS-type PKS) were compared with expression of an internal control mitochondrial small subunit gene (mtSSU). The results showed that media containing yeast extracts produced the largest colony diameters and the fewest number of secondary metabolites. Colony growth rates also varied with different media conditions, and a significant negative relationship occurred between colony diameter and number of secondary metabolites. Expression of the NR PKS gene was significantly higher at pH 6.5 on the glucose malt agar than any other media, and expression of the 6-MSAS-type (partially-reducing) PKS gene was significantly higher at pH 8.5 on (malt agar) malt agar than on the other types of agar. Gene expression was correlated with the pH level and media conditions that induced the production of the larger number of secondary substances. This is the first study to examine secondary metabolite production in R. dilacerata by comparing the number of polyketides detected with quantitative polymerase chain reaction (qPCR) of two PKS genes under different culture conditions.     

Secondary metabolism of pharmaceuticals in the plant in vitro cultures: strategies,approaches, and limitations to achieving higher yield

Biotechnology is playing a vital alternative role in the production of pharmaceutical plant secondary metabolites to support industrial production and mitigate over-exploitation of natural sources. High-value pharmaceuticals that include alkaloids, flavonoids, terpenes, steroids, among others, are biosynthesized as a defensive strategy by plants in response to perturbations under natural environmental conditions. However, they can also be produced using plant cell, tissue, and organ culture techniques through the application of various in vitro approaches and strategies. In the past decades, efforts were on the clonal propagation, biomass and secondary metabolites production in the in vitro cultures of medicinally important plants that produce these molecules. In recent years, the effort has shifted towards optimizing culture conditions for their production through the application of cell line selection, elicitation, precursor feeding, two-phase co-culture among cell, tissue, and organ culture approaches. The efforts are made with the possibility to scale-up the production, meet pharmaceutical industry demand and conserve natural sources of the molecules. Applications of metabolic engineering and production from endophytes are also getting increasing attention but, the approaches are far from practical application in their industrial production.     

Secondary metabolism of hairy root cultures in bioreactors

Summary In vitro cultures are being considered as an alternative to agricultural processes for producing valuable secondary metabolites. Most efforts that use differentiated cultures instead of cell suspension cultures have focused on transformed (hairy) roots. Bioreactors used to culture hairy roots can be roughly divided into three types: liquid-phase, gas-phase, or hybrid reactors that are a combination of both. The growth and productivity of hairy root cultures are reviewed with an emphasis on successful bioreactors and important culture considerations. The latter include strain selection, production of product in relation to growth phase, media composition, the gas regime, use of elicitors, the role of light, and apparent product loss. Together with genetic engineering and process optimization, proper reactor design plays a key role in the development of successful large scale production of secondary metabolites from plant cultures.     

TOPICAL PAPER: Utilization of Hairy Root Cultures for Production of Secondary Metabolites

The possibility of producing useful chemicals by plant cell cultures has been studied intensively for the past 30 years. However, problems associated with low product yields and culture instabilities have restricted wider industrial application of plant cell culture. The employment of hairy root culture technology, developed in the past 10 years, offers new opportunities for in vitro production of plant secondary metabolites. In contrast to cell suspension cultures, hairy root cultures are characterized by high biosynthetic capacity and genetic as well as biochemical stability. In this review, the establishment and cultivation of hairy root cultures as well as their properties and application for production of secondary metabolites are discussed.     

Adventitious Roots and Secondary Metabolism

Plants are a rich source of valuable secondary metabolites and in the recent years plant cell, tissue and organ cultures have been developed as an important alternative sources for the production of these compounds. Adventitious roots have been successfully induced in many plant species and cultured for the production of high value secondary metabolites of pharmaceutical, nutraceutical and industrial importance. Adoption of elicitation methods have shown improved synthesis of secondary metabolites in adventitious root cultures. Development of large-scale culture methods using bioreactors has opened up feasibilities of production of secondary metabolites at the industrial levels. In the present review we summarize the progress made in recent past in the area of adventitious root cultures for the production of secondary metabolites.     

Adventitious Roots and Secondary Metabolism

Plants are a rich source of valuable secondary metabolites and in the recent years plant cell, tissue and organ cultures have been developed as an important alternative sources for the production of these compounds. Adventitious roots have been successfully induced in many plant species and cultured for the production of high- value secondary metabolites of pharmaceutical, nutraceutical and industrial importance. Adoption of elicitation methods have shown improved synthesis of secondary metabolites in adventitious root cultures. Development of large-scale culture methods using bioreactors has opened up feasibilities of production of secondary metabolites at the industrial levels. In the present review we summarize the progress made in recent past in the area of adventitious root cultures for the production of secondary metabolites.