Our research focuses on memory processes in plants which are induced by developmental or environmental cues. Transitions in the plant lifecycle such as germination, the transition from embryonic to vegetative growth, and flowering, the transition from vegetative to reproductive growth, are usually very stable so that embryonic traits or vegetative traits, respectively, are suppressed after a phase transition. Similarly, recurring stress such as pathogen attack or adverse temperature may create a memory so that plants which have been exposed to a stress are more resistant to a subsequent stressful event, a phenomenon termed “priming”. As the memory is usually reset every generation, developmental or stress memory cannot rely on changes of DNA sequence and therefore rely on epigenetic mechanisms.
We aim to identify the molecular mechanisms and factors which control developmental memory and reveal the cell types in which the memory occurs. We use genetic, molecular and biochemical techniques combined with advanced imaging and (epi)genomics for our studies. Knowledge of the mechanisms underlying memory processes in plants may contribute to control and stabilize phase transitions for higher fruit and seed yield and enhance the resistance of plants to recurring stress. Our team is a member of the Dahlem Centre of Plant Sciences, one of the research focus areas of the FU-Berlin.
During growth of plants and animals, cell and organ identity and switches in cell fate need to be maintained throughout the lifecycle. This is particularly relevant in plants were environmentally induced phase transitions occur, such as the transition from embryonic to vegetative growth, termed germination, and the transition from vegetative to reproductive growth, termed flowering. Similarly, recurring stress such as pathogen attack or adverse temperature may create a memory so that plants which have been exposed to a stress are more resistant to a subsequent stressful event, a phenomenon termed “priming”. Priming and memory are studied the SFB973.
Cell fate transitions and stress memory can be stable through cell divisions, but are usually reset in each generation. Therefore, epigenetic mechanisms - stable, heritable changes that occur without alterations in the DNA sequence - play a major role in the control and maintenance of cell fate and likely also in stress memory.
Key regulators of the epigenetic control of cell fate are the Polycomb-group (Pc-G) proteins and their antagonists, the Trithorax-group (Trx-G) proteins. These proteins are conserved in all multicellular organisms and have many important functions including roles in cancer and stem cell control. Plant Pc-G proteins control many economically and developmentally important traits including seed and flower development, flowering time and meristem identity and are generally required to maintain cell fate. Pc-G proteins act on chromatin via tri-methylation of lysine 27 of histone H3 (H3K27me3). Although Pc-G proteins have been extensively studied, it is still not known – specifically in plants - how these proteins are recruited to their target genes and how the histone methylation marks confer stable gene silencing. It is therefore important to identify additional players that mediate Pc-G silencing in plants.
The lab is interested in contributing to the following aspects of epigenetics: