Brassinosteroid in growth control and stress responses
Plants constantly adapt to changes in their environment to adjust their growth and development to increase their chances of survival. Hormones play an important role in adapting plant development to external conditions, and one class of hormones is the brassinosteroids (BR), which are similar in structure to human and animal steroid hormones. BRs promote cell elongation and control essential development processes, such as root and shoot development, biomass increase, flowering time control, and fruit development and ripening. However, they also play a decisive role in the ability of plants to develop resistance against stress, a process called stress acclimation.
A central goal of our research is to clarify how BRs regulate growth, in particular in terms of adaptation to environmental factors. We also aim to understand how BRs function in plants when abiotic stress, triggered by extreme temperatures such as heat and frost, or biotic stress, triggered by fungal and bacterial pathogens, prevails. We elucidate molecular and biochemical mechanisms that make it possible to regulate BR concentrations, investigate factors that control BR signal transduction, and study the interaction of BRs with other hormones, such as gibberellins and abscisic acid.
In our work, we use models such as the thale cress Arabidopsis thaliana and test whether our findings can be transferred to crops such as cultivated tomato Solanum lycopersicum.
Selected publications:
Albertos, P., Duendar, G., Schenk, P., Carrera, A., Cavelius, P., Sieberer, T., & Poppenberger, B. (2022) Transcription factor BES1 interacts with HSFA1 to promote heat stress resistance of plants.
EMBO J. 3108664
Eremina, M., Unterholzner, S.J., Rozhon, W., Kugler, K.G., Castellanos, M., Ratnajaka, A., Khan, M., May, S., Mayer, K.M. & Poppenberger, B. (2016) Brassinosteroids contribute to the control of basal and acquired freezing tolerance in plants.
Proc. Natl. Acad. Sci. USA 113: E5982-91
Unterholzner ,S.J., Rozhon, W., Papacek, M., Lange, T., Kugler, K.G., Mayer, K.M., Sieberer, T. & Poppenberger, B. (2015) Brassinosteroids Are Master Regulators of Gibberellin Biosynthesis in Arabidopsis.
Plant Cell 27: 2261-72
Khan, M., Rozhon, W., Unterholzner, S.J., Chen, T., Eremina, M., Wurzinger, B., Bachmair, A., Teige, M., Sieberer, T., Isono, E. & Poppenberger, B. (2014) Interplay between phosphorylation and SUMOylation events determines CESTA protein fate in brassinosteroid signalling.
Nature Communic. 5: 4687
Poppenberger, B., Rozhon, W., Khan, M., Husar, S., Adam, G., Luschnig, C., Fujioka, S. & Sieberer, T. (2011) CESTA a positive regulator of brassinosteroid biosynthesis.
EMBO J. 30: 1149-61