Dr. Franziska Fichtner

As sessile organisms, land plants must constantly sense and allocate their resources to maximise growth, reproduction, and survival. Sugars are central to this process: they not only provide carbon and energy, but also act as key regulatory molecules. In most vascular plants, sucrose is the major product of photosynthesis and the primary sugar transported from source tissues to growing sinks.

My research centres on trehalose 6-phosphate (Tre6P), a pivotal regulator of sucrose homeostasis that links sugar availability with developmental decisions. I discovered that Tre6P is produced mainly in the vasculature (Fig. 1b), where it shapes flowering time and plant architecture across annual and perennial species (Fig. 1c). These findings highlight Tre6P as a major systemic cue in vascular plants. Supporting this, Tre6P-related genes expanded during land plant evolution, coinciding with the emergence of vascular tissues and long-distance transport (Fig. 1d).

My current work investigates Tre6P and sugar-regulated pathways across the green lineage. Ultimately, I aim to uncover the core mechanisms that connect plant metabolism with growth, one of the major goals within CEPLAS.

1. Göbel M, Foster J, Westhoff P, Skorzinski N, Lepper HL, Njo MF, Schmid M, Beeckman T, Tanurdžić M, Amtmann A, Fichtner F (2025) Systemic and local regulation of root growth by vascular trehalose 6-phosphate is correlated with re-allocation of primary metabolites between shoots and roots. bioRxiv:2025.2011.2013.688188. doi: 10.1101/2025.11.13.688188.
2. Fichtner F (2025) Trehalose 6-phosphate - a central regulator at the crossroads of sugar signalling, metabolism, and development. New Phytol 248(5):2243-2250. doi: 10.1111/nph.70533.
3. Fichtner F, Humphreys JL, Barbier FF, Feil R, Westhoff P, Moseler A, Lunn JE, Smith SM, Beveridge CA (2024) Strigolactone signalling inhibits trehalose 6-phosphate signalling independently of BRC1 to suppress shoot branching. New Phytol 244(3):900-913. doi: 10.1111/nph.20072.
4. Fichtner, F, Barbier, F, Annunziata, M, Feil, R, Olas, J, Mueller‐Roeber, B, Stitt, M, Beveridge, CA, and Lunn, JE (2021). Regulation of shoot branching in Arabidopsis by trehalose 6‐phosphate. New Phytologist 229: 2135–2151.
5. Fichtner, F, and Lunn, JE (2021). The role of trehalose 6-phosphate (Tre6P) in plant metabolism and development. Annual Review of Plant Biology 72: 737-760.

6. Fichtner, F, Olas, JJ, Feil, R, Watanabe, M, Krause, U, Höfgen, R, Stitt, M, Lunn, JE (2020). Functional features of TREHALOSE-6-PHOSPHATE SYNTHASE1 - an essential enzyme in Arabidopsis thaliana.The Plant Cell 32: 1949-1972.