TY - JOUR A1 - Senf, Deborah A1 - Ruprecht, Colin A1 - Kishani, Saina A1 - Matic, Aleksandar A1 - Toriz, Guillermo A1 - Gatenholm, Paul A1 - Wagberg, Lars A1 - Pfrengle, Fabian T1 - Tailormade polysaccharides with defined branching patterns BT - Enzymatic polymerization of arabinoxylan oligosaccharides JF - Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition N2 - The heterogeneous nature of non-cellulosic polysaccharides, such as arabinoxylan, makes it difficult to correlate molecular structure with macroscopic properties. To study the impact of specific structural features of the polysaccharides on crystallinity or affinity to other cell wall components, collections of polysaccharides with defined repeating units are required. Herein, a chemoenzymatic approach to artificial arabinoxylan polysaccharides with systematically altered branching patterns is described. The polysaccharides were obtained by glycosynthase-catalyzed polymerization of glycosyl fluorides derived from arabinoxylan oligosaccharides. X-ray diffraction and adsorption experiments on cellulosic surfaces revealed that the physicochemical properties of the synthetic polysaccharides strongly depend on the specific nature of their substitution patterns. The artificial polysaccharides allow structure-property relationship studies that are not accessible by other means. KW - carbohydrates KW - enzymes KW - glycosynthases KW - structure elucidation KW - synthetic methods Y1 - 2018 U6 - https://doi.org/10.1002/anie.201806871 SN - 1433-7851 SN - 1521-3773 VL - 57 IS - 37 SP - 11987 EP - 11992 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Ruprecht, Colin A1 - Lohaus, Rolf A1 - Vanneste, Kevin A1 - Mutwil, Marek A1 - Nikoloski, Zoran A1 - Van de Peer, Yves A1 - Persson, Staffan T1 - Revisiting ancestral polyploidy in plants JF - Science Advances N2 - Whole-genome duplications (WGDs) or polyploidy events have been studied extensively in plants. In a now widely cited paper, Jiao et al. presented evidence for two ancient, ancestral plant WGDs predating the origin of flowering and seed plants, respectively. This finding was based primarily on a bimodal age distribution of gene duplication events obtained from molecular dating of almost 800 phylogenetic gene trees. We reanalyzed the phylogenomic data of Jiao et al. and found that the strong bimodality of the age distribution may be the result of technical and methodological issues and may hence not be a "true" signal of two WGD events. By using a state-of-the-art molecular dating algorithm, we demonstrate that the reported bimodal age distribution is not robust and should be interpreted with caution. Thus, there exists little evidence for two ancient WGDs in plants from phylogenomic dating. Y1 - 2017 U6 - https://doi.org/10.1126/sciadv.1603195 SN - 2375-2548 VL - 3 PB - American Assoc. for the Advancement of Science CY - Washington ER - TY - JOUR A1 - Ruprecht, Colin A1 - Mutwil, Marek A1 - Saxe, Friederike A1 - Eder, Michaela A1 - Nikoloski, Zoran A1 - Persson, Staffan T1 - Large-scale co-expression approach to dissect secondary cell wall formation across plant species JF - Frontiers in plant science N2 - Plant cell walls are complex composites largely consisting of carbohydrate-based polymers, and are generally divided into primary and secondary walls based on content and characteristics. Cellulose microfibrils constitute a major component of both primary and secondary cell walls and are synthesized at the plasma membrane by cellulose synthase (CESA) complexes. Several studies in Arabidopsis have demonstrated the power of co-expression analyses to identify new genes associated with secondary wall cellulose biosynthesis. However, across-species comparative co-expression analyses remain largely unexplored. Here, we compared co-expressed gene vicinity networks of primary and secondary wall CESAsin Arabidopsis, barley, rice, poplar, soybean, Medicago, and wheat, and identified gene families that are consistently co-regulated with cellulose biosynthesis. In addition to the expected polysaccharide acting enzymes, we also found many gene families associated with cytoskeleton, signaling, transcriptional regulation, oxidation, and protein degradation. Based on these analyses, we selected and biochemically analyzed T-DNA insertion lines corresponding to approximately twenty genes from gene families that re-occur in the co-expressed gene vicinity networks of secondary wall CESAs across the seven species. We developed a statistical pipeline using principal component analysis and optimal clustering based on silhouette width to analyze sugar profiles. One of the mutants, corresponding to a pinoresinol reductase gene, displayed disturbed xylem morphology and held lower levels of lignin molecules. We propose that this type of large-scale co-expression approach, coupled with statistical analysis of the cell wall contents, will be useful to facilitate rapid knowledge transfer across plant species. KW - secondary cell wall KW - comparative co-expression analysis KW - Arabidopsis KW - cellulose Y1 - 2011 U6 - https://doi.org/10.3389/fpls.2011.00023 SN - 1664-462X VL - 2 PB - Frontiers Research Foundation CY - Lausanne ER - TY - THES A1 - Ruprecht, Colin T1 - Characterization of genetic modules involved in cellulose synthesis in Arabidopsis thaliana Y1 - 2011 CY - Potsdam ER -