PD Dr. Frank Waller

Research area

Plant-microbe interactions

Molecular mechanisms of plant pathogen resistance

Plant sphingolipids and sphingobases

Programmed cell death in plants

Bachelor / Master students:  Interested in a practical training or thesis project? Contact me!

The Team

Alina Voss, Kristina Erwardt, Frank Waller, Stefanie Schmidt, Hannah Weber

Analysis of Sphingolipids during plant pathogen responses and abiotic stress

Programmed cell death is an important mechanism used by plants to stop the spread of biotrophic pathogens in the tissue. We have shown that bacteria-triggered programmed cell death in Arabidopsis is associated with elevated levels of the sphingobase phytosphingosine. We are now investigating whether phytosphingosine plays a role as a signaling molecule in the plant defense response. We are also testing whether phytosphingosine can inhibit the growth of plant pathogens.

Environmental conditions also significantly affect the levels of specific sphingolipids. For the functional study of sphingolipids in plants we use an extensive collection of Arabidopsis mutants and overexpressor lines. These allow us to track down the function of specific sphingolipids in the plant under defined stress conditions.

Previous publications:

Peer M, Bach M, Mueller MJ, Waller F (2011) Free sphingobases induce RBOHD-dependent reactive oxygen species production in Arabidopsis leaves. FEBS letters 585: 3006-3010

Peer M, Stegmann M, Mueller M, Waller F (2010) Pseudomonas syringae infection triggers de novo synthesis of phytosphingosine from sphinganine in Arabidopsis thaliana. Febs Letters 584: 4053-4056

Improving plant pathogen resistance by root-colonising endophytic fungi

Serendipita indica (Piriformospora indica) and Serendipita herbamans, fungi of the order Sebacinales, colonize the roots of many plant species. This colonization can increase pathogen resistance of the host plant, not only in the roots, but also in the leaves (systemic resistance). In addition, colonization can lead to accelerated development and increased yield of the plant. We investigate the molecular mechanisms underlying this improvement in plant resistance and differences in plant responses to symbionts and pathogens.

Previous publications:

Weiss M, Waller F, Zuccaro A, Selosse MA (2016) Sebacinales - one thousand and one interactions with land plants. New Phytol 211: 20-40

Pedrotti L, Mueller MJ, Waller F (2013) Piriformospora indica root colonization triggers local and systemic root responses and inhibits secondary colonization of distal roots. PLoS One 8: e69352

Molitor A, Zajic D, Voll LM, Pons KHJ, Samans B, Kogel KH, Waller F (2011) Barley leaf transcriptome and metabolite analysis reveals new aspects of compatibility and Piriformospora indica-mediated systemic induced resistance to powdery mildew. Molecular plant-microbe interactions : MPMI 24: 1427-1439

Deshmukh S, Huckelhoven R, Schafer P, Imani J, Sharma M, Weiss M, Waller F, Kogel KH (2006) The root endophytic fungus Piriformospora indica requires host cell death for proliferation during mutualistic symbiosis with barley. Proceedings of the National Academy of Sciences of the United States of America (PNAS) 103: 18450-18457

Waller F, Achatz B, Baltruschat H, Fodor J, Becker K, Fischer M, Heier T, Huckelhoven R, Neumann C, von Wettstein D, Franken P, Kogel KH (2005) The endophytic fungus Piriformospora indica reprograms barley to salt-stress tolerance, disease resistance, and higher yield. Proceedings of the National Academy of Sciences of the United States of America (PNAS) 102: 13386-13391

Latest publications

Lambour B, Glenz R, Forner C, Krischke M, Mueller MJ, Fekete A, Waller F (2022) Sphingolipid Long-Chain Base Phosphate Degradation Can Be a Rate-Limiting Step in Long-Chain Base Homeostasis. Frontiers in plant science, Vol 13, p 911073

Garnica S, Liao Z, Hamard S, Waller F, Parepa M, Bossdorf O (2022) Environmental stress determines the colonization and impact of an endophytic fungus on invasive knotweed. Biological Invasions 24: 1785-1795

Vera M, Zuern S, Henríquez-Valencia C, Loncoman C, Canales J, Waller F, Basoalto E, Garnica S (2022) Exploring interactions between Beauveria and Metarhizium strains through co-inoculation and responses of perennial ryegrass in a one-year trial. PeerJ, Vol 10, p e12924

Glenz R, Kaiping A, Göpfert D, Weber H, Lambour B, Sylvester M, Fröschel C, Mueller MJ, Osman M, Waller F (2022) The major plant sphingolipid long chain base phytosphingosine inhibits growth of bacterial and fungal plant pathogens. Scientific reports, Vol 12, p 1081

Fröschel C, Komorek J, Attard A, Marsell A, Lopez-Arboleda WA, Le Berre J, Wolf E, Geldner N, Waller F, Korte A, Dröge-Laser W (2021) Plant roots employ cell-layer-specific programs to respond to pathogenic and beneficial microbes. Cell host & microbe 29: 299-310.e297

Osman M, Stigloher C, Mueller MJ, Waller F (2020) An improved growth medium for enhanced inoculum production of the plant growth-promoting fungus Serendipita indica. Plant methods, Vol 16, p 39

Inaji A, Okazawa A, Taguchi T, Nakamoto M, Katsuyama N, Yoshikawa R, Ohnishi T, Waller F, Ohta D (2020) Rhizotaxis Modulation in Arabidopsis Is Induced by Diffusible Compounds Produced during the Cocultivation of Arabidopsis and the Endophytic Fungus Serendipita indica. Plant & cell physiology 61: 838-850

Glenz R, Schmalhaus D, Krischke M, Mueller MJ, Waller F (2019) Elevated Levels of Phosphorylated Sphingobases Do Not Antagonize Sphingobase- or Fumonisin B1-Induced Plant Cell Death. Plant Cell Physiol 60: 1109-1119

About me

I received my Ph.D. (Biology) at the Albert-Ludwigs-Universität Freiburg i.Br., Germany. Studies abroad included stays in China, Taiwan and Japan.

I worked at the Nara Institute of Science and Technology (NAIST), Nara, Japan as a postdoctoral fellow and worked as a group leader at the Faculty of Agricultural Sciences, Justus-Liebig-Universität Giessen, Germany.

Since 2009 I am leading a small research group at the Chair of Pharmaceutical Biology, Julius-Maximilians-Universität Würzburg.

Testing stress resistance of different Arabidopsis mutant lines

Funding by

Our project 'Functional characterisation of sphingobase and sphingolipid metabolism and the role of sphingobases in plant programmed cell death'  was funded until early 2019 by a grant from the Deutsche Forschungsgemeinschaft (DFG).

Previous research was supported by: DFG, Alexander von Humboldt Stiftung / Japanese Society for the Promotion of Science (JSPS),  Ostasien-Stipendienprogramm der Daimler Benz AG / Studienstiftung des deutschen Volkes,  Deutscher Akademischer Austauschdienst (DAAD).