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Ana M. Calvo Richard A. Wilson Jin Woo Bok Nancy P. Keller 《Microbiological reviews》2002,66(3):447-459
Filamentous fungi are unique organisms—rivaled only by actinomycetes and plants—in producing a wide range of natural products called secondary metabolites. These compounds are very diverse in structure and perform functions that are not always known. However, most secondary metabolites are produced after the fungus has completed its initial growth phase and is beginning a stage of development represented by the formation of spores. In this review, we describe secondary metabolites produced by fungi that act as sporogenic factors to influence fungal development, are required for spore viability, or are produced at a time in the life cycle that coincides with development. We describe environmental and genetic factors that can influence the production of secondary metabolites. In the case of the filamentous fungus Aspergillus nidulans, we review the only described work that genetically links the sporulation of this fungus to the production of the mycotoxin sterigmatocystin through a shared G-protein signaling pathway. 相似文献
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During development, animals usually undergo a rapid growth phase followed by a homeostatic stage when growth has ceased. The increase in cell size and number during the growth phase requires a large amount of lipids; while in the static state, excess lipids are usually stored in adipose tissues in preparation for nutrient-limited conditions. How cells coordinate growth and fat storage is not fully understood. Through a genetic screen we identified Drosophila melanogaster CDP-diacylglycerol synthetase (CDS/CdsA), which diverts phosphatidic acid from triacylglycerol synthesis to phosphatidylinositol (PI) synthesis and coordinates cell growth and fat storage. Loss of CdsA function causes significant accumulation of neutral lipids in many tissues along with reduced cell/organ size. These phenotypes can be traced back to reduced PI levels and, subsequently, low insulin pathway activity. Overexpressing CdsA rescues the fat storage and cell growth phenotypes of insulin pathway mutants, suggesting that CdsA coordinates cell/tissue growth and lipid storage through the insulin pathway. We also revealed that a DAG-to-PE route mediated by the choline/ethanolamine phosphotransferase Bbc may contribute to the growth of fat cells in CdsA RNAi. 相似文献
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Aiyada Aroonsri Shigeru Kitani Junko Hashimoto Ikuko Kosone Miho Izumikawa Mamoru Komatsu Nobuyuki Fujita Yoko Takahashi Kazuo Shin-ya Haruo Ikeda Takuya Nihira 《Applied and environmental microbiology》2012,78(22):8015-8024
The γ-butyrolactone autoregulator signaling cascades have been shown to control secondary metabolism and/or morphological development among many Streptomyces species. However, the conservation and variation of the regulatory systems among actinomycetes remain to be clarified. The genome sequence of Kitasatospora setae, which also belongs to the family Streptomycetaceae containing the genus Streptomyces, has revealed the presence of three homologues of the autoregulator receptor: KsbA, which has previously been confirmed to be involved only in secondary metabolism; KsbB; and KsbC. We describe here the characterization of ksbC, whose regulatory cluster closely resembles the Streptomyces virginiae barA locus responsible for the autoregulator signaling cascade. Deletion of the gene ksbC resulted in lowered production of bafilomycin and a defect of aerial mycelium formation, together with the early and enhanced production of a novel β-carboline alkaloid named kitasetaline. A putative kitasetaline biosynthetic gene cluster was identified, and its expression in a heterologous host led to the production of kitasetaline together with JBIR-133, the production of which is also detected in the ksbC disruptant, and JBIR-134 as novel β-carboline alkaloids, indicating that these genes were biosynthetic genes for β-carboline alkaloid and thus are the first such genes to be discovered in bacteria. 相似文献
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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. 相似文献
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Adventitious Roots and Secondary Metabolism 总被引:2,自引:0,他引:2
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. 相似文献
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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。 相似文献
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《Cell cycle (Georgetown, Tex.)》2013,12(6):709-712
Growth and differentiation are two major themes in embryonic development. Numerous cell divisions have to be regulated on the path from a unicellular embryo, the zygote, to the multicellular structures of a mature being. Numerous functions, specializations and cellular identities have to be generated, in order to form a complex and mature animal. Numerous mechanisms have to control the correct assignment and acquisition of cellular fates, as well as the right timing and allocation of cells. Therefore, a strict coordination has to occur between embryonic patterning and the cell cycle. From this point of view, dual roles or mutual interactions of typical proliferation and developmental control genes are likely. Recently, new light was shed on these issues by identifying the nuclear protein Geminin as a molecular coordinator between the cell cycle and axial patterning. We summarize the role of Geminin in cell cycle, in the embryonic patterning controlled by Hox genes, providing insights into cell cycle regulators in embryonic development, and, conversely, typical developmental control genes in cell cycle regulation. 相似文献
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链霉菌次级代谢调控机制进展 总被引:1,自引:0,他引:1
链霉菌除具有复杂的形态分化特征外 ,还可以产生多种具有重要应用价值的次级代谢产物 ,这两个过程密切相关。因此 ,链霉菌存在着原核生物中罕见的庞大而复杂的调控网络。链霉菌在遗传水平有三个层次的调控 ,分别是 :途径特异性调控、多效调控和全局调控。阐明这些调控网络将为利用代谢工程手段提高次级代谢产物的产量并对其进行结构改造奠定理论基础 ,还将有助于发现新的有价值的天然产物。 相似文献
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《Critical reviews in biotechnology》2013,33(3):191-204
AbstractThe Gram-positive bacterial genus Streptomyces possesses interesting biological aspects, such as the ability to produce a wide variety of secondary metabolites and a mycelial form of growth that culminates in sporulation. A close relationship of secondary metabolism and cell differentiation has been well recognized; secondary metabolism might be a physiological expression of cell differentiation. A variety of diffusible low-molecular-weight chemical substances have been found to function in general as regulatory factors, like “hormones” in eukaryotes, for secondary metabolism and cell differentiation. Among these factors, A-factor has been most extensively studied. This review summarizes recent research on the chemical structures, functions, biosyntheses, and mode of action of these regulatory factors. 相似文献
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植物萜类次生代谢及其调控 总被引:5,自引:0,他引:5
植物次生代谢在植物生长发育、环境适应、抵御病虫害等方面发挥着重要作用,这些天然产物组成地球上最丰富的有机化合物的宝库.萜类是植物代谢产物中种类最多的一类,具有重要的生理和生态功能,一些成分还有应用价值.近十几年来,人们在萜类化合物的分离、鉴定、应用、生物合成、相关基因与基因族、酶蛋白结构和功能、代谢调控以及代谢工程等各方面取得了重大进展.本文概述了植物萜类化合物代谢及其调控领域的研究进展与发展趋势. 相似文献
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