A publication by scientists from the Institute of Molecular and Industrial Biotechnology – Maciej Nielipiński, M.Sc., Agnieszka Pietrzyk-Brzezińska, Ph.D., and Bartosz Sekuła, Ph.D., D.Sc. – was honored by the Crystallography Committee of the Polish Academy of Sciences with the prestigious title “Crystallographic Diamond” in the category of biological and medical crystallography. In this article, the authors present the results of their research and explain its significance.
War for Crops
Modern agriculture faces many challenges that cause significant crop losses every year. Sudden climate changes contribute not only to more frequent natural disasters but also to the spread of plant diseases and pests. Plant protection products are essential to maintaining healthy and abundant yields, but their use requires proper knowledge and caution to minimize negative impacts on the environment, humans, and beneficial organisms.
An increasing problem is the weeds resistant to currently used herbicides. As a result, many popular products lose effectiveness or are withdrawn from the market for safety reasons.
These challenges motivated research into previously uncharacterized metabolic pathways in plants. Further study and understanding of plant enzyme structures will allow identifying attractive molecular targets against which new, effective, and safe plant protection agents can be designed in the future.
X-ray crystallography allows us to look deeply into the protein structure, like through a powerful magnifying glass. Thanks to it, we learn the structure of enzymes and how they carry out chemical reactions.
Key Enzyme in Plant Metabolism
Our research focused on the enzyme ornithine transcarbamylase (OTC), which plays a key role in nitrogen metabolism in plants. We discovered how OTC opens and closes its catalytic center – the site where substrates bind and where chemical reactions occur. This enzyme is the target of bacteria from the genus Pseudomonas, which cause, among others, halo blight of bean – a disease leading to serious crop losses. Although this phenomenon is catastrophic for plants, a similar mechanism can be used to develop new herbicides effectively combating weeds.
The secret weapon of Pseudomonas syringae against OTC is a toxin called phaseolotoxin. It acts like a saboteur – blocking the OTC enzyme, a key enzyme in the arginine biosynthesis pathway, an amino acid essential for proper plant development and metabolism.