Developmental PhysiologyDr. Steffen Greiner
Many higher plants accumulate fructans as storage carbohydrates. These fulfill diverse physiological functions in plants but are also a valuable resource for humans with a wide range of applications.
In collaboration with industrial partners, we are investigating the molecular physiology of sucrose and fructan metabolism (inulin type) in chicory, which serves as a model but also can be used industrially. The aim of this project is to understand the regulation of inulin metabolism as comprehensively as possible and thus provide a basis for targeted breeding of chicory to improve inulin content and composition.
Inulin metabolism in Chicory
Inulin is used as carbohydrate storage compound in plants but may also be involved in several stress responses. The economically most important source is chicory, which accumulates inulin in its taproots. Biotechnological goals are to increase inulin yield and its degree of polymerization (DP). Enzymes responsible for inulin biosynthesis in chicory are sucrose:sucrose 1-fructosyltransferase (1-SST) and fructan:fructan 1-fructosyltransferase (1-FFT), inulin degradation is catalyzed by fructan 1-exohydrolases (1-FEHs). We are investigating the post-translational as well as transcriptional control of FAZYs. Through bioinformatic analysis, we identified transcription factors that play crucial roles in stress-mediated regulatory aspects of fructan metabolism. We investigate TF networks with chicory plants grown in the greenhouse and under field conditions and compare different chicory genotypes with varying fructan accumulation. Results from this research will provide fundamentally new insight into fructan metabolism and may open new routes for biotechnology. In this context, we also establish CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) / Cas Technology with in vitro cultured chicory plants for in planta verification of the results. Additionally, we have established the chicory hairy root culture (CiHRC) as a model system to explore regulatory mechanisms impacting on inulin metabolism in planta.
Greenhouse gases and plants
Another line of research is the contribution of plants to the global budget of greenhouse gases. Nitrous oxide and methane play a crucial role here, for while they occur in much lower concentrations than carbon dioxide, they are far more potent.
In recent years, it has become apparent that both nitrous oxide and methane can be produced in plants depending on various environmental factors. Together with our cooperation partners, we are trying to elucidate the mechanism and better quantify the share in the global budget of these gases.
- Huang, X.; Luo, W.; Wu, S.; Long, Y.; Li, R.; Zheng, F.; Greiner, S.; Rausch, T.; Zhao, H. 2020 Apoplastic maize fructan exohydrolase Zm-6-FEH displays substrate specificity for levan and is induced by exposure to levan-producing bacteria Int J Biol Macromol 163 630-639 doi: 10.1016/j.ijbiomac.2020.06.254
- Lenhart, K., Behrendt, T., Greiner, S., Steinkamp, J., Well, R., Giesemann, A. and Keppler, F. (2019), Nitrous oxide effluxes from plants as a potentially important source to the atmosphere. New Phytol, 221: 1398-1408. doi: 10.1111/nph.15455
- Wei, H.; Bausewein, A.; Greiner, S.; Dauchot, N.; Harms, K.; Rausch, T. 2017 CiMYB17, a stress-induced chicory R2R3-MYB transcription factor, activates promoters of genes involved in fructan synthesis and degradation New Phytol 215 1 281-298 doi: 10.1111/nph.14563
- Su, T.; Wolf, S.; Han, M.; Zhao, H.; Wei, H.; Greiner, S.; Rausch, T. 2016 Reassessment of an Arabidopsis cell wall invertase inhibitor AtCIF1 reveals its role in seed germination and early seedling growth Plant Mol Biol 90 1-2 137-155 doi: 10.1007/s11103-015-0402-2
- Wei, H.; Bausewein, A.; Steininger, H.; Su, T.; Zhao, H.; Harms, K.; Greiner, S.; Rausch, T. 2016 Linking Expression of Fructan Active Enzymes, Cell Wall Invertases and Sucrose Transporters with Fructan Profiles in Growing Taproot of Chicory (Cichorium intybus): Impact of Hormonal and Environmental Cues Front Plant Sci 7 1806 doi: 10.3389/fpls.2016.01806
- Althoff, F.; Benzing, K.; Comba, P.; McRoberts, C.; Boyd, D.R.; Greiner, S.; Keppler, F. 2014 Abiotic methanogenesis from organosulphur compounds under ambient conditions Nat Commun 5 4205 doi: 10.1038/ncomms5205
- Wolf, S.; van der Does, D.; Ladwig, F.; Sticht, C.; Kolbeck, A.; Schurholz, A.-K.; Augustin, S.; Keinath, N.; Rausch, T.; Greiner, S.; Schumacher, K.; Harter, K.; Zipfel, C.; Hofte, H. 2014 A receptor-like protein mediates the response to pectin modification by activating brassinosteroid signaling Proc Natl Acad Sci U S A 111 42 15261-15266 doi: 10.1073/pnas.1322979111
- Wolf, S.; Mravec, J.; Greiner, S.; Mouille, G.; Hofte, H. 2012 Plant cell wall homeostasis is mediated by brassinosteroid feedback signaling Curr Biol 22 18 1732-1737 doi: 10.1016/j.cub.2012.07.036
- Wolf, S.; Greiner, S. 2012 Growth control by cell wall pectins Protoplasma 249 Suppl 2 S169-75 doi: 10.1007/s00709-011-0371-5
- Siemens, J.; Gonzalez, M.-C.; Wolf, S.; Hofmann, C.; Greiner, S.; DU, Y.; Rausch, T.; Roitsch, T.; Ludwig-Muller, J. 2011 Extracellular invertase is involved in the regulation of clubroot disease in Arabidopsis thaliana Mol Plant Pathol 12 3 247-262 doi: 10.1111/j.1364-3703.2010.00667.x
- Wishkerman, A.; Greiner, S.; Ghyczy, M.; Boros, M.; Rausch, T.; Lenhart, K.; Keppler, F. 2011 Enhanced formation of methane in plant cell cultures by inhibition of cytochrome c oxidase Plant Cell Environ 34 3 457-464 doi: 10.1111/j.1365-3040.2010.02255.x
- Kusch, U.; Harms, K.; Rausch, T.; Greiner, S. 2009 Inhibitors of plant invertases do not affect the structurally related enzymes of fructan metabolism New Phytol 181 3 601-612 doi: 10.1111/j.1469-8137.2008.02688.x
- Kusch, U.; Greiner, S.; Steininger, H.; Meyer, A.D.; Corbiere-Divialle, H.; Harms, K.; Rausch, T. 2009 Dissecting the regulation of fructan metabolism in chicory (Cichorium intybus) hairy roots New Phytol 184 1 127-140 doi: 10.1111/j.1469-8137.2009.02924.x
- Wolf, S.; Rausch, T.; Greiner, S. 2009 The N-terminal pro region mediates retention of unprocessed type-I PME in the Golgi apparatus Plant J 58 3 361-375 doi: 10.1111/j.1365-313X.2009.03784.x
- Rockel, N.; Wolf, S.; Kost, B.; Rausch, T.; Greiner, S. 2008 Elaborate spatial patterning of cell-wall PME and PMEI at the pollen tube tip involves PMEI endocytosis, and reflects the distribution of esterified and de-esterified pectins Plant J 53 1 133-143 doi: 10.1111/j.1365-313X.2007.03325.x
- Hothorn, M.; D'Angelo, I.; Marquez, J.A.; Greiner, S.; Scheffzek, K. 2004 The invertase inhibitor Nt-CIF from tobacco: a highly thermostable four-helix bundle with an unusual N-terminal extension J Mol Biol 335 4 987-995
- Hothorn, M.; Wolf, S.; Aloy, P.; Greiner, S.; Scheffzek, K. 2004 Structural insights into the target specificity of plant invertase and pectin methylesterase inhibitory proteins Plant Cell 16 12 3437-3447 doi: 10.1105/tpc.104.025684
- Link, M.; Rausch, T.; Greiner, S. 2004 In Arabidopsis thaliana, the invertase inhibitors AtC/VIF1 and 2 exhibit distinct target enzyme specificities and expression profiles FEBS Lett 573 1-3 105-109 doi: 10.1016/j.febslet.2004.07.062
- Rausch, T.; Greiner, S. 2004 Plant protein inhibitors of invertases Biochim Biophys Acta 1696 2 253-261 doi: 10.1016/j.bbapap.2003.09.017
- Hothorn, M.; Bonneau, F.; Stier, G.; Greiner, S.; Scheffzek, K. 2003 Bacterial expression, purification and preliminary X-ray crystallographic characterization of the invertase inhibitor Nt-CIF from tobacco Acta Crystallogr D Biol Crystallogr 59 Pt 12 2279-2282
- Wolf, S.; Grsic-Rausch, S.; Rausch, T.; Greiner, S. 2003 Identification of pollen-expressed pectin methylesterase inhibitors in Arabidopsis FEBS Lett 555 3 551-555
- Rosenkranz, H.; Vogel, R.; Greiner, S.; Rausch, T. 2001 In wounded sugar beet (Beta vulgaris L.) tap-root, hexose accumulation correlates with the induction of a vacuolar invertase isoform J Exp Bot 52 365 2381-2385