URL: http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B8JG4-50W1TS4-33&_cdi=43660&_user=4296857&_pii=S1871678410005583&_origin=search&_coverDate=08%2F26%2F201 0&_sk=999999999&view=c&wchp=dGLbVtbzSkWb&md5=17b2002443f27e7ec31a02b1e8f75c80&ie=/sdarticle.pdf Author Address: Institute of Plant Biotechnology for Developing Countries (IPBO), Department of Molecular Genetics, Ghent University, K.L. Ledeganckstraat 35, 9000 Gent, Belgium XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX Author: Vanholme R, Ralph J, Akiyama T, Lu F, Pazo JR, Kim H, Christensen JH, Van Reusel B, Storme V, De Rycke R, Rohde A, Morreel K, Boerjan W, Year: 2010 Title: * Engineering traditional monolignols out of lignin by concomitant F5H1-up- and COMT-downregulation in Arabidopsis. Journal: The Plant Journal - Article first published online: 29 AUG 2010. Pages: no Label: Composition Nutrition Keywords: lignin cell wall benzodioxane NMR phenolic profiling mutants Abstract: Lignin engineering is a promising strategy to optimize lignocellulosic plant biomass for use as a renewable feedstock for agro-industrial applications. Current efforts focus on engineering lignin with monomers that are not normally incorporated into wild-type lignins. We report an Arabidopsis line in which the lignin is derived to a major extent from a non-traditional monomer. The combination of a caffeic acid Omethyltransferase (comt) mutation with FERULATE 5-HYDROXYLASE1 (F5H1) over-expression (C4H:F5H1) resulted in plants with a unique lignin composed of nearly 92% benzodioxane units. In addition to the biosynthesis of this peculiar lignin, the comt C4H:F5H1 plants revealed massive shifts in phenolic metabolism when compared to the wild type. The structures of 38 metabolites that accumulated in comt C4H:F51 plants were resolved by mass spectral analyses and shown to derive from 5-hydroxy-substituted phenylpropanoids. These metabolites probably originate from passive metabolism via existing biochemical routes normally used for 5-methoxylated and 5-unsubstituted phenylpropanoids and from active detoxification by hexosylation. Transcripts of the phenylpropanoid biosynthesis were highly up-regulated in comt C4H:F5H1 plants, indicating feedback regulation within the pathway. To investigate the role of flavonoids in the abnormal growth of comt C4H:F5H1 plants, a chalcone synthase (chs) mutation was crossed in. The resulting comt C4H:F5H1 chs plants were partially restored in growth. However, a causal connection between flavonoid deficiency and this resurrection could not be shown; rather, genetic interactions between phenylpropanoid and flavonoid biosynthesis could explain the partial resurrection. These genetic interactions need to be taken into account in future cell wall engineering strategies. URL: http://dx.doi.org/10.1111/j.1365-313X.2010.04353.x Author Address: 1Department of Plant Systems Biology, VIB, 9052 Gent, Belgium 2Department of Plant Biotechnology and Genetics, Ghent University, 9052 Gent, Belgium 3Department of Biochemistry, and Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, Wisconsin 53706, USA XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX Author: Verma AK, Upadhyay SK, Verma PC, Solomon S, Singh SB, Year: 2010 Title: * Functional analysis of sucrose phosphate synthase (SPS) and sucrose synthase (SS) in sugarcane (Saccharum) cultivars. Journal: Plant Biology Article first published online: 26 AUG 2010 Pages: no Label: Composition Nutrition Physiol Keywords: Hexose sugars SPS SS sucrose transcript expression Abstract: Sucrose phosphate synthase (SPS; EC 2.4.1.14) and sucrose synthase (SS; EC 2.4.1.13) are key enzymes in the synthesis and breakdown of sucrose in sugarcane. The activities of internodal SPS and SS, as well as transcript expression were determined using semi-quantitative RT-PCR at different developmental stages of high and low sucrose accumulating sugarcane cultivars. SPS activity and transcript expression was
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