Biosynthetic origin of 2-geranyl-1,4-naphthoquinone and its related anthraquinone in a Sesamum indicum hairy root culture. Phytochem
ABSTRACT In order to clarify the biosynthetic origin of 2-geranyl-1,4-naphthoquinone and its biogenetically related anthraquinone, which are possible intermediates of anthrasesamones, [1-(13)C]glucose was administered to a hairy root culture of Sesamum indicum. The labeling patterns of these quinone derivatives indicated that the naphthoquinone ring and geranyl side-chain of geranylnaphthoquinone were respectively biosynthesized through the shikimate and methylerythritol phosphate pathways, and that these quinone derivatives have the same biosynthetic origin.
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ABSTRACT: When compared to other organisms, plants are atypical with respect to isoprenoid biosynthesis: they utilize two distinct and separately compartmentalized pathways to build up isoprene units. The co-existence of these pathways in the cytosol and in plastids might permit the synthesis of many vital compounds, being essential for a sessile organism. While substrate exchange across membranes has been shown for a variety of plant species, lack of complementation of strong phenotypes, resulting from inactivation of either the cytosolic pathway (growth and development defects) or the plastidial pathway (pigment bleaching), seems to be surprising at first sight. Hundreds of isoprenoids have been analyzed to determine their biosynthetic origins. It can be concluded that in angiosperms, under standard growth conditions, C₂₀-phytyl moieties, C₃₀-triterpenes and C₄₀-carotenoids are made nearly exclusively within compartmentalized pathways, while mixed origins are widespread for other types of isoprenoid-derived molecules. It seems likely that this coexistence is essential for the interaction of plants with their environment. A major purpose of this review is to summarize such observations, especially within an ecological and functional context and with some emphasis on regulation. This latter aspect still requires more work and present conclusions are preliminary, although some general features seem to exist.Progress in lipid research 12/2011; 51(2):95-148. DOI:10.1016/j.plipres.2011.12.001 · 12.96 Impact Factor
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ABSTRACT: The content of anthrasesamone C (5), a rare chlorine-containing anthraquinone, in a hairy root culture of Sesamum indicum increased with increasing chloride ion concentration in the culture medium and reached a maximum at 100 mM. However, the amount of anthrasesamone C (5) in the extract obtained from the hairy roots was increased by incubating the extract. This result suggests that anthrasesamone C (5) was produced from an unidentified metabolite by an abiotic process. 2,3-Epoxyanthrasesamone B (1), a precursor for the non-enzymatic formation of anthrasesamone C (5), was isolated from S. indicum hairy roots cultured in a chloride-deficient medium. Its structure was elucidated to be 2,3-epoxy-9,10-dihydroxy-2-(4-methylpent-3-en-1-yl)-2,3-dihydroanthracene-1,4-dione by spectroscopic methods.Bioscience Biotechnology and Biochemistry 02/2012; 76(2):305-8. DOI:10.1271/bbb.110688 · 1.21 Impact Factor
Chapter: Neglected Oil Crop Biotechnology[Show abstract] [Hide abstract]
ABSTRACT: Global food security has become increasingly dependent on only a handful of crops cultivated intensively leading to crop replacement and a massive reduction in the number of species and diversity of crops. This poses a threat to local and global food security because the replaced indigenous crops are often essential for low input agriculture, have unique nutritional value, and contain diversity of locally adapted genotypes with resistance to a wide array of biotic and abiotic stresses. Most of these plant species are important locally or regionally only, and are known as ‘minor’, ‘neglected’, ‘underexploited’ or ‘underutilized’ crops. Like many other crops, production of oilseeds has not improved significantly due to their susceptibility to pests, sensitivity to abiotic stresses and low nutrient use efficiency. An approach for meeting the increasing demand for vegetable oils will be to introduce new or underutilized oilseed crops that are more suited for cultivation on less fertile land that do not support production of major oilseed crops. A need also exists for dedicated non-food oilseed crops that can be used for metabolic engineering of novel oil compositions for industrial applications. A number of oilseeds have recently received attention for their potential to fill one or more of these niches. These include Ironweed (Vernonia galamensis), crambe (Crambe abyssinica), desert mustard (Lesquerella fendleri), niger (Guizotia abyssinica), camelina (Camelina sativa), the Ethiopian mustard (Brassica carinata) and Sesame (Sesamum indicum). In this chapter emphasis has been given to current biotechnology research and progress for the improvement of these neglected oil crops. Agricultural biotechnology is creating new tools to tackle the problems of crop improvement, rural poverty, employment and income generation by helping to enhance farm productivity and production, improve quality, and explore marketing opportunities in newer ways. Technology like tissue culture provides the means for the culture of protoplasts, ovules and embryos used to create new genetic variation by overcoming reproductive barriers between distantly related crop species and haploid production by the culture of anthers and microspores to shorten the selection cycle in a breeding programme. Characterization of genetic diversity by molecular markers is important for devising effective sampling and conservation strategies. Molecular markers can also be used to certify varieties, to determine the presence or absence of diseases and development of linkage maps for identifying quantitative trait loci and marker assisted selection. Transferred genes through genetic engineering may contribute to a range of properties, including resistance/tolerance to biotic and abiotic factors, improved nutritional status and better management options.Biotechnology of Neglected and Underutilized Crops, Edited by Shri Mohan Jain, S. Dutta Gupta, 01/2013: pages 117-172; Springer.