Soy substitute: Cultivation of lupins as protein plants in NRW - the new P3roLucas project

Like beans and peas, lupins belong to the legumes and they are a valuable source of protein and a good alternative to the mostly imported soybeans. Lupine is cultivated in Germany as a fodder plant and is becoming increasingly important for human (vegan/vegetarian) nutrition. There are now, for example, lupine ice cream, lupine fillets, lupine milk and yoghurt, lupine noodles and vegan egg substitutes made from lupine flour in the supermarkets.

Lupins are cultivated in Germany since a long time. In the 1990s, anthracnose disease, which is caused by fungi, became a major problem. The breeding and use of resistant or tolerant varieties (e.g. blue lupine, resistant white lupine varieties) can help against this disease, which causes large crop losses. Another way to stabilize lupine varieties against such diseases and adverse environmental conditions are so-called biostimulants. Biostimulants are substances and also microorganisms that strengthen plants and make them more resistant to diseases and environmental stresses.

The cultivation of lupin in Germany is currently focussed on Brandenburg, Mecklenburg-Western Pomerania, Saxony and Saxony-Anhalt, whereas in NRW only ca. 3% of the total area of lupin-culivation is found [1]. In July 2022, the P³roLucas project started with participation of the IBG-4. This project funded by the BioSC, aims to increase the cultivation of lupins as a crop in NRW. To reach this, different cultivars and their reaction to biostimulants are investigated at the project coordinator Dr. Loehrer at the RWTH Aachen. With this improvements in cultivation practice can be established as a measure against biotic and abiotic stress. At the IBG-4, genomes of lupine genotypes are investigated and partially re-sequenced. In order to understand the molecular basis of the action of the biostimulants and their interaction with the different cultivars, gene expression studies are carried out. This should make it possible to take the interaction with biostimulants into account in further breeding. The factors required for the acceptance of lupine cultivation in combination with the use of biostimulants are being investigated in the working group of Prof. Hartmann at the University of Bonn.

Many lupine cultivars contain a high level of alkaloids, a distinction is made between so-called sweet and bitter lupines, the sweet lupines are low in bitter substances. The bitter substances are toxic to livestock and to humans in food. While the sweet lupin cultivars can be used directly for food, the alkaloids in the bitter lupins are first removed in a technical process. In a cascade utilization approach, the accumulating alkaloid-rich "waste water" will be used in P3roLucas in the research group of Dr. Classen at IBOC at the University of Düsseldorf to extract the pharmaceutically and chemically interesting quinolizidine alkaloids, such as lupanine. Furthermore, chemical transformations of these alkaloids will be investigated. For example, the resulting lupanine can be converted to sparteine, which can be used very well as a chiral ligand in chemical reactions and can also be of pharmaceutical use. Information on other alkaloids identified in the aqueous extractions will be studied with the data on genes and their expression in the cultivars to understand the biosynthetic pathways and their regulation. P3roLucas will thus address and support lupine cultivation in North Rhine-Westphalia in its entire range from cultivation, plant protection and processing to cascade use for chemical syntheses and as food/animal feed, taking into account the acceptance by farmers.

Project coordination:

Prof. U. Schaffrath und Dr. M. Löhrer, Department of Plant Physiology (Biology III), RWTH Aachen University

Projekt partner:

• Prof. J. Pietruszka und Dr. T. Classen, IBOC - Bioorganic Chemistry, HHU Düsseldorf
• Prof. M. Hartmann und Dipl.-Oecotroph. J. Klink-Lehmann, Department of Agricultural and Food Market Research, University of Bonn

P³roLucas is part of the NRW-Strategieprojekt BioSC and is funded from the Ministry of Culture and Science of the State of North Rhine-Westphalia as a BOOST FUND 2.0 project for three years.

[1] Wachstum und Ernte – Feldfrüchte – Fachserie 3 Reihe 3.2.1 (www.destatis.de)