One of the primary carbon sinks in plants is the hemicellulose component of the cell wall. Using a synthetic biology approach, the plant genes involved in the biosynthesis of these polysaccharides are expressed in orthologous systems such as yeast, enabling the replication of polymer production. This strategy not only provides critical insights into the mechanisms and carbon flux underlying polysaccharide biosynthesis, but also enables the generation of novel polymers—previously unseen in nature—with modified biophysical properties, paving the way for the development of unique biomaterials.

Markus Pauly

The properties and functions of polysaccharides are significantly influenced by acetate side chains. We have identified several plant genes involved in the addition of acetate groups to these polymers. Through a combination of approaches—including the use of plant mutants, heterologous expression in yeast, targeted mutagenesis, and protein structural models—we aim to unravel the mechanism of polysaccharide O-acetylation, a process also relevant in bacterial and fungal pathogen systems.

Vicente Ramirez, Markus Pauly

Altering the structure and architecture of plant cell walls, such as in certain plant mutants, often results in significant growth or developmental defects, along with activation of pathogen defense responses. These abnormalities are typically caused by the plant's stress-sensing mechanisms, which trigger compensatory responses. Using a suppressor mutant approach, we have identified protein factors that disrupt the perception of these stress signals, allowing the plants to maintain relatively normal growth despite their modified cell wall structure.

Vicente Ramirez

Finite, greenhouse gas-emitting fossil fuels need to be replaced with sustainable, carbon-neutral alternatives such as agricultural waste, which is both highly abundant and underutilized. This includes leaf and stem biomass from crops like maize, most of which is composed of plant cell wall material known as lignocellulose. Our goal is to identify non-transgenic, cost-effective maize varieties that yield higher levels of sugar from lignocellulosic biomass when processed as whole plants. To achieve this, we use approaches such as mutagenesis, breeding, and large-scale sequencing.

Markus Pauly, Vicente Ramirez

The bulk of agricultural residues is made up of lignocellulosic materials—non-edible plant matter containing sugars that, once extracted, can be converted into commodity chemicals. A major obstacle in this process is the inherent resistance of lignocellulosics to breakdown. Our approach involves identifying, selecting, optimizing, and monitoring biomass processing steps to pinpoint key plant genes that improve processing efficiency. The resulting patentable insights can be readily applied to other crops, particularly grasses like wheat and barley, and may ultimately support targeted breeding strategies aimed at increasing the yield of usable plant residues.

Markus Pauly, Vicente Ramirez

Interactions and recognition between organisms are often facilitated by plasma membrane receptors that bind specific carbohydrate ligands. For example, in lichens, the fungal partner (mycobiont) recognizes and binds to the algal or cyanobacterial partner (photobiont) through such mechanisms. Similarly, when plants are attacked by pathogens, fragments of the plant cell wall are released and detected by plant receptors, triggering defense responses. In our research, we investigate the detailed structure of these carbohydrate ligands using advanced carbohydrate analysis techniques, while also exploring receptor specificity through a yeast display system.

Vicente Ramirez, Markus Pauly 

What would a plant organ optimized for maximal carbon fixation and storage look like? How could the functional cell types within this tissue be engineered for peak performance? By integrating optogenetic control systems, plant cell cultures, and 3D bioprinting, we aim to design and construct such an artificial, high-efficiency tissue.

Markus Pauly