Project archive
Selection of our most important completed research projects
This project studies the key step in the biosynthesis of phloridzin, which is the prevalent polyphenolic compound in apple. Phloridzin represents more than 90% of the soluble phenolic compounds in apple leaves. The presence of such high amounts of phloridzin makes apple unique since other species accumulate only very low amounts and many closely related species like pear are not able to form phloretin or its glucosylated relative phloridzin. The last decade has seen an explosion of research on the beneficial effects of phloretin and phloridzin for human health but the physiological relevance for apple is still unclear. A possible involvement in disease resistance is discussed. Previously we have shown with apple leaf extracts that phloridzin formation is based on three biosynthetic steps: (1) the formation of dihydro-p-coumaroyl-CoA from p-coumaroyl-CoA by a dehydrogenase, (2) further formation of phloretin by the common chalcone synthase and (3) the glucosylation of phloretin in position 2’. Whereas the last two steps were already intensively studied, the knowledge of the first step is limited. The enzyme is crucial, because it seems to be the key point making the phloridzin-hoarding apple unique in comparison to other plants. In our previous FWF project (P25399-B16) we successfully completed a challenging purification process and were able to purify for the first time a candidate enzyme from apple leaves, which exhibits strong enzyme activity with p-coumaroyl-CoA to form dihydro-p-coumaroyl-CoA. The planned follow-up project will now target the detailed characterization of this important enzyme from apple leaves for the first time. Structural studies will resolve the enzymatic mechanism, such as protein crystallization and effects of substrates, inhibitors/effectors or other factors. The DNA sequence of the dehydrogenase will be isolated from apple and transferred into bacteria to produce large amounts of the enzyme for detailed characterization. It will be tested, in which tissue and developmental stage the dehydrogenase gene is switched on or off. Functional activity of the gene products will be tested with genetically modified plants where phloretin formation will be enabled by the dehydrogenase in thale cress (Arabidopsis) or disabled in apple. Comparison of the DNA and protein sequence of the dehydrogenase from different plant species will give insight to structure-activity relationship of the enzyme on the molecular level. The project members consist of three teams which provide complementary know-how and resources: One of the Austrian teams offers knowledge in phloridzin biosynthesis, molecular biology and enzymatic evaluation, the other Austrian team has profound experience in protein characterization and crystallisation, whereas the German team provides the infrastructure and long-term experience in the creation of transgenic plants. An external team from New Zealand, which is funded by own sources will additionally contribute its know-how on pear transformation.
Funding: FWF - Austrian Science Fund and DFG - Deutsche Forschungsgemeinschaft
Project number: I 4296
Duration: 01.05.2020 – 30.04.2024
Contact: Senior Scientist Dipl.-Ing. Dr.rer.nat. Christian Haselmair-Gosch
PUBLICATIONS
Cebulj A, Mikulic-Petkovsek M, Lucaciu C, Veberic R, Marinovic S, Kolarek M, Hutabarat OS, Faramarzi S, Rattei T, Molitor C, Hudina M, Haselmair-Gosch C, Halbwirth H, Slatnar A. (2021). Alteration of the phenylpropanoid pathway by watercore disorder in apple (Malus x domestica). Scientia Horticulturae, https://doi.org/10.1016/j.scienta.2021.110438, opens an external URL in a new window
Weissensteiner J, Molitor C, Marinovic S, Führer L, Waqas Hassan S, Hutabarat OS, Spornberger A, Stich K, Hausjell J, Spadiut O, Haselmair-Gosch C, Halbwirth H. (2021). Molecular and Enzymatic Characterization of Flavonoid 3'-Hydroxylase of Malus × domestica. Plants (Basel, Switzerland), 10(9), https://doi.org/10.3390/plants10091956, opens an external URL in a new window
Schröpfer S., Molitor C., Haselmair-Gosch C., Flachowsky H., Stich K., Halbwirth H. (2022). XXXI International Horticultural Congress (IHC2022): International Symposium on Breeding and Effective Use of Biotechnology and Molecular Tools in Horticultural Crops. 31st International Horticultural Congress: International Symposium on Breeding and Effective Use of Biotechnology and Molecular Tools in Horticultural Crops.
Schröpfer S., Molitor C., Haselmair-Gosch C., Flachowsky H., Stich K., Halbwirth H. (2023). Polyphenols Communications e-vol. 2. The International Conference on Polyphenols (ICP).
Schröpfer S., Molitor C., Böttcher C., Haselmair-Gosch C., Flachowsky H., Halbwirth H. (2023). Validation of a candidate gene involved in the biosynthesis of phloridzin in apple by heterologous expression in Arabidopsis thaliana. XVI Eucarpia Symposium on Fruit Breeding and Genetics.
Kornpointner C., Miksovsky P., Rabeeah I.A., Murray H., Goessinger M., Haselmair-Gosch C., Stich K., Bica-Schroeder K., Halbwirth H. (2023). Polyphenols Communications e-vol. 2. The International Conference on Polyphenols (ICP).
Kniely J. (2021). Molecularbiological and biochemical investigations on the dihydrochalcone biosynthesis in apple leaves. Bachelor thesis
Metzgen M. (2020). Herstellung und Charakterisierung von rekombinanten Cytochrom-P450-abhängigen Proteinen aus Angelonien und Apfel. Bachelorarbeit
Schmidt-Gruber V. (2024). Hinter die Schale geschaut: Verteilung von Phloridzin in verschiedenen Apfelteilen und Untersuchungen zu seiner antioxidativen Wirkung. Bachelorarbeit
Schöpf M. (2022). Untersuchungen zur Reaktion der Chalkonsynthase. Diplomarbeit
This project studies the key step in the biosynthesis of phloridzin, which is the prevalent polyphenolic compound in apple. Phloridzin represents more than 90% of the soluble phenolic compounds in apple leaves. The presence of such high amounts of phloridzin makes apple unique since other species accumulate only very low amounts and many closely related species like pear are not able to form phloretin or its glucosylated relative phloridzin. The last decade has seen an explosion of research on the beneficial effects of phloretin and phloridzin for human health but the physiological relevance for apple is still unclear. A possible involvement in disease resistance is discussed. Previously we have shown with apple leaf extracts that phloridzin formation is based on three biosynthetic steps: (1) the formation of dihydro-p-coumaroyl-CoA from p-coumaroyl-CoA by a dehydrogenase, (2) further formation of phloretin by the common chalcone synthase and (3) the glucosylation of phloretin in position 2’. Whereas the last two steps were already intensively studied, the knowledge of the first step is limited. The enzyme is crucial, because it seems to be the key point making the phloridzin-hoarding apple unique in comparison to other plants. In our previous FWF project (P25399-B16) we successfully completed a challenging purification process and were able to purify for the first time a candidate enzyme from apple leaves, which exhibits strong enzyme activity with p-coumaroyl-CoA to form dihydro-p-coumaroyl-CoA. The planned follow-up project will now target the detailed characterization of this important enzyme from apple leaves for the first time. Structural studies will resolve the enzymatic mechanism, such as protein crystallization and effects of substrates, inhibitors/effectors or other factors. The DNA sequence of the dehydrogenase will be isolated from apple and transferred into bacteria to produce large amounts of the enzyme for detailed characterization. It will be tested, in which tissue and developmental stage the dehydrogenase gene is switched on or off. Functional activity of the gene products will be tested with genetically modified plants where phloretin formation will be enabled by the dehydrogenase in thale cress (Arabidopsis) or disabled in apple. Comparison of the DNA and protein sequence of the dehydrogenase from different plant species will give insight to structure-activity relationship of the enzyme on the molecular level. The project members consist of three teams which provide complementary know-how and resources: One of the Austrian teams offers knowledge in phloridzin biosynthesis, molecular biology and enzymatic evaluation, the other Austrian team has profound experience in protein characterization and crystallisation, whereas the German team provides the infrastructure and long-term experience in the creation of transgenic plants. An external team from New Zealand, which is funded by own sources will additionally contribute its know-how on pear transformation.
Funding: FWF - Austrian Science Fund
Project number: P 32901
Duration: 01.01.2020 – 31.12.2023
Contact: Associate Prof. Dipl.-Ing. Dr.in techn. Heidi Halbwirth
PUBLICATIONS
Walliser, Benjamin, Silvija Marinovic, Christoph Kornpointner, Christopher Schlosser, Mustafa Abouelnasr, Olly Sanny Hutabarat, Christian Haselmair-Gosch, Christian Molitor, Karl Stich, and Heidi Halbwirth. "The (Bio) chemical Base of Flower Colour in Bidens ferulifolia." Plants 11, no. 10 (2022): 1289. https://doi.org/10.3390/plants11101289, opens an external URL in a new window
Weissensteiner, Julia, Christian Molitor, Silvija Marinovic, Lisa Führer, Syed Waqas Hassan, Olly Sanny Hutabarat, Andreas Spornberger, Karl Stich, Johanna Hausjell, Oliver Spadiut, Christian Haselmair-Gosch, and Heidi Halbwirth "Molecular and Enzymatic Characterization of Flavonoid 3′-Hydroxylase of Malus × domestica." Plants 10, no. 9 (2021): 1956. https://doi.org/10.3390/plants10091956, opens an external URL in a new window
Walliser, Benjamin, Calin Rares Lucaciu, Christian Molitor, Silvija Marinovic, Daria Agata Nitarska, Didem Aktaş, Thomas Rattei, Ioannis Kampatsikas, Karl Stich, Christian Haselmair-Gosch and Heidi Halbwirth "Dahlia variabilis cultivar ‘Seattle’ as a model plant for anthochlor biosynthesis." Plant Physiology and Biochemistry 159 (2021): 193-201. https://doi.org/10.1016/j.plaphy.2020.12.016, opens an external URL in a new window
Nitarska, D., Boehm, R., Debener, T., Lucaciu, R. C., & Halbwirth, H. (2021). First genome edited poinsettias: targeted mutagenesis of flavonoid 3′-hydroxylase using CRISPR/Cas9 results in a colour shift. Plant Cell, Tissue and Organ Culture (PCTOC), 1-12. https://doi.org/10.1007/s11240-021-02103-5, opens an external URL in a new window
Cebulj, Anka, Maja Mikulic-Petkovsek, Calin Rares Lucaciu, Robert Veberic, Silvija Marinovic, Martina Kolarek, Olly Sanny Hutabarat, Shadab Faramarzi, Thomas Rattei, Christian Molitor, Metka Hudina, Christian Haselmair-Gosch, Heidi Halbwirth, and Ana Slatnar "Alteration of the phenylpropanoid pathway by watercore disorder in apple (Malus x domestica)." Scientia Horticulturae 289 (2021): 110438, https://doi.org/10.1016/j.scienta.2021.110438, opens an external URL in a new window
Hausjell, Johanna, Julia Weissensteiner, Christian Molitor, Karin Schlangen, Oliver Spadiut, and Heidi Halbwirth. "First purified recombinant CYP75B including transmembrane helix with unexpected high substrate specificity to (2R)-naringenin." Scientific Reports 12, no. 1 (2022): 1-13. DOI: https://doi.org/10.1038/s41598-022-11556-3, opens an external URL in a new window
Funding: WWTF Vienna Science and Technology Fund
Project number: ESR17-027
Duration: 01.03.2018 – 28.02.2023
Contact: Associate Prof. Dipl.-Ing. Dr.in techn. Heidi Halbwirth
Funding: FWF - Austrian Science Fund
Project number: I 2919
Duration: 2017 - 2021
Contact: Associate Prof. Dipl.-Ing. Dr.in techn. Heidi Halbwirth
Funding: European Commission, Horizon2020
Project number: 675657
Duration: 2016 - 2020
Contact: Associate Prof. Dipl.-Ing. Dr.in techn. Heidi Halbwirth
Funding: FWF - Austrian Science Fund
Project number: P 29552
Duration: 2016 - 2019
Contact: Associate Prof. Dipl.-Ing. Dr.in techn. Heidi Halbwirth
Funding: FWF - Austrian Science Fund
Project number: P 28795
Duration: 2016 - 2019
Contact: Associate Prof. Dipl.-Ing. Dr.in techn. Heidi Halbwirth
Funding: FWF - Austrian Science Fund
Project number: P 28134
Duration: 2015 - 2020
Contact: Senior Scientist Dipl.-Ing. Dr.rer.nat. Christian Haselmair-Gosch
Funding: FWF - Austrian Science Fund
Project number: P 26468
Duration: 2014 - 2018
Contact: Ao.Univ.-Prof.i.R. Dipl.-Ing. Dr.nat.techn. Karl Stich
Funding: FWF - Austrian Science Fund
Project number: P 25399
Duration: 2013 - 2018
Contact: Associate Prof. Dipl.-Ing. Dr.in techn. Heidi Halbwirth
Funding: FWF - Austrian Science Fund
Project number: P 24331
Duration: 2012 - 2015
Contact: Associate Prof. Dipl.-Ing. Dr.in techn. Heidi Halbwirth
Funding: European Commission (Euphresco)
Project number: 100867
Duration: 2012 - 2014
Contact: Ao.Univ.-Prof.i.R. Dipl.-Ing. Dr.nat.techn. Karl Stich
Funding: Austrian Federal Ministry for Economy, Family and Youth (PRIZE 2010)
Project number: Z100355
Duration: 2012 - 2014
Contact: Ao.Univ.-Prof.i.R. Dipl.-Ing. Dr.nat.techn. Karl Stich
Funding: Austrian Federal Ministry of Agriculture, Forestry, Environment and Water Management
Project number: 100404
Duration: 2008 - 2011
Contact: Ao.Univ.-Prof.i.R. Dipl.-Ing. Dr.nat.techn. Karl Stich
Funding: Gesellschaft zur Förderung von Pflanzenforschung
Duration: 2008
Contact: Associate Prof. Dipl.-Ing. Dr.in techn. Heidi Halbwirth
Funding: FWF - Austrian Science Fund
Project number: V18-B03
Duration: 2006 - 2011
Contact: Associate Prof. Dipl.-Ing. Dr.in techn. Heidi Halbwirth
Funding: European Commission
Project number:
Duration: 2006 - 2010
Contact: Associate Prof. Dipl.-Ing. Dr.in techn. Heidi Halbwirth
Funding: European Science Foundation
Project number: COST Action 864
Duration: 2006 - 2010
Contact: Ao.Univ.-Prof.i.R. Dipl.-Ing. Dr.nat.techn. Karl Stich
Funding: FWF - Austrian Science Fund
Project number: P 17629
Duration: 2004 - 2006
Contact: Associate Prof. Dipl.-Ing. Dr.in techn. Heidi Halbwirth
Funding: Hochschuljubiläumsstiftung der Stadt Wien
Project number:
Duration: 2002 - 2004
Contact: Associate Prof. Dipl.-Ing. Dr.in techn. Heidi Halbwirth
Funding: European Commission
Project number: QLK5-CT-1999-01583
Duration: 2000 – 2003
Contact: Ao.Univ.-Prof.i.R. Dipl.-Ing. Dr.nat.techn. Karl Stich
Funding: FWF - Austrian Science Fund
Project number: P 13020
Duration: 1999 - 2000
Contact: Ao.Univ.-Prof.i.R. Dipl.-Ing. Dr.nat.techn. Karl Stich
Funding: Jubiläumsfonds der Österreichischen Nationalbank
Project number:
Duration: 1999 - 2000
Contact: Associate Prof. Dipl.-Ing. Dr.in techn. Heidi Halbwirth