Arabidopsis and Capsella
In the coming years, the team will initially focus on the two species Arabidopsis and Capsella. Arabidopsis thaliana, also known as thale cress or mouse-ear cress, is a fast-growing weed. It is used as a model plant in genetic research because it has a small, well-characterized genome that can be easily modeled. The species is widely distributed, robust, and grows under a variety of conditions. Capsella, also known as shepherd’s purse, is related to Arabidopsis. It is used as a wild lettuce and medicinal plant and is an annual to biennial herbaceous plant with characteristic small “siliques” shaped like the purses of early shepherds, hence the name. Capsella illustrates some common processes in plants.
“Arabidopsis is the most studied plant in the world,” Prof. Lenhard emphasizes. It is already known that its leaves and flowers develop differently depending on the ambient temperature. At a temperature of 17 degrees Celsius, for example, the leaves tend to be elongated, while at 22 degrees Celsius they tend to be round. In Capsella, different temperatures lead to different leaf shapes and either jagged or smooth leaf edges. A subproject of the CRC identifies the genes underlying these different leaf shapes so that desired characteristics can be bred in the future through gene selection.
Countering heat stress
In the greenhouse on the Golm campus, the species Capsella grandiflora can be admired with its delicate white flowers. Here, specimens are bred that are either self-pollinating or attract insects as pollinators. The plants growing in Golm and possessing many different genotypes are the starting point for so-called selection experiments. The current experiment focuses on the tolerance of plants to heat stress, which depends on the environment in which they previously grew. Some of the plants’ predecessors come from Greece, where it is hotter and drier than in Germany. Their phenotype shows a higher tolerance to heat. Isabel Bäurle, Professor of Epigenetics, heads the respective subproject and is interested in the molecular causes. “We know that there are different genotypes that react differently to the environment, and we want to understand why,” she explains.
In other experiments, the researchers are breeding 200 plant types with different genetic material in various settings, under low and high temperatures, with a lot or little daylight, and in nutrient-rich or nutrient-poor soil. The supply of nitrogen to the plants influences their appearance and especially their growth. Root hairs play a decisive role in nutrient uptake and adapt to the nitrogen concentration. In a further subproject, the root-hair properties of Arabidopsis are therefore being investigated with regard to their adaptability.
Modeling metabolic processes
Since many questions about Arabidopsis in the same environment have already been answered, it is now easier to study the species in different environments. “Another big advantage of Arabidopsis is that we use very accurate and robust metabolic models in the CRC that are better than for many crop species,” Küken adds.
The modeling groups at the CRC primarily work with plant metabolism, which includes all biochemical reactions within a plant and is driven by photosynthesis. Metabolic processes control the reproduction and growth of plants. “With our models, we investigate how quickly certain metabolic products – metabolites – are converted into others and how this activity differs between different plants,” Küken says. “This enables us to better understand dependencies in the complex system of metabolism and investigate their effects on plant growth.” In her subproject, she is particularly interested in the plasticity of the Calvin-Benson cycle in Arabidopsis in response to changing light and nitrogen availability over a daily cycle. The Calvin-Benson cycle is a biochemical process in plants in which carbon dioxide is converted into glucose. It is also known as the dark reaction of photosynthesis.
“The models often still require a lot of experimental data to train and improve them,” she explains. For this purpose, the so-called omics sciences are used, which deal with the biological molecules involved in the structure, function, and dynamics of cells and organisms: genomics researches the genetic information of an organism, proteomics examines all proteins within an organism, while metabolomics analyzes the intermediate and end products of metabolism.
The ultimate goal is to be able to describe the environmental response for each genotype. Some genotypes change their metabolism very significantly and are thus able to maintain an almost constant growth rate. Others react sensitively in terms of growth to lower water or nitrogen availability. “We want to understand how these changes are related to a higher tolerance to water or nitrogen deficiency,” Lenhard says.
Focusing on career development
Anika Küken is also committed to the interests of young researchers within the CRC. “We offer various courses and training opportunities for our doctoral students and postdocs, as well as networking opportunities such as the regular ‘Meet-the-Speaker Lunch’ with experts from the CRC community,” she says. To gain practical experience beyond research, doctoral students and postdocs from the CRC organized the two-day “International Conference on Phenotypic Plasticity in Plants” in October 2025 at the Wissenschaftsetage of the Bildungsforum Potsdam. “In November 2025, there will also be a day for women in science, which will provide a platform for networking and discussions about careers and family,” Küken adds.
In addition to the 17 scientific subprojects, the CRC 1644 consists of a synthesis project and a central administration project. The enormous amounts of data that will be collected over the coming years must be stored, managed, analyzed, and integrated. Bioinformatics Professor Zoran Nikoloski, Vice-Spokesperson of the CRC, and Christoph Lippert, Professor at the Digital Engineering Faculty of the University of Potsdam and an expert in machine learning, perform this fundamental task. Since the CRC is designed for cross-institutional collaboration between universities and research institutions, the synthesis project provides the necessary interface to enable all participants to access every data set that will be created. “By examining different levels, we hope to ultimately identify connections that would not have been found through individual projects,” Prof. Lenhard summarizes.
Michael Lenhard has been Professor of Genetics at the University of Potsdam since 2010.
Anika Küken has been a research assistant at the Chair of Bioinformatics at the University of Potsdam since 2020.
Identical twins originate from the same fertilized egg and have the same genetic information—they are of the same genotype. However, if they grow under different environmental influences, they can develop differently over the course of their lives, for example in terms of physique, abilities, or preferences. As a result, identical twins sometimes do not look identical in adulthood. This ability of genetically identical organisms – animals and plants alike – is referred to as phenotypic plasticity.
The Collaborative Research Center 1644 “Phenotypic Plasticity in Plants” investigates the remarkable ability of plants to adapt their growth and development to different environments.
Further information on the Collaborative Research Center 1644 : https://www.uni-potsdam.de/en/ppp