Measuring plant resistance
The scientists at the Leibniz Institute of Plant Biochemistry (IPB) are set to launch a new interdisciplinary research program in January 2023, which will consolidate existing capacities in high-performance analytical instruments with expertise in the fields of bioorganic chemistry, metabolomics, and chemo- and bioinformatics. The aim of the Program Center for Plant Metabolomics and Computational Biochemistry (MetaCom) is to gain a comprehensive understanding of plant resilience at a chemical level.
As part of the MetaCom implementation, the Institute has a one-time opportunity to hire a total of 13 scientists, data managers and technical assistants. The MetaCom Center will also get a visible shell, with plans to construct a multifunctional building with offices and laboratories that will house scientists and administrative staff.
A sedentary existence by nature underlines the need for plants to have exceptional defense and adaptation mechanisms to obtain sufficient nutrients or withstand danger and disease. Since they cannot run away, they fight back chemically. In fact, they can produce a vast arsenal of substances, ranging from colorants, odors and flavors to vitamins, antibiotics and highly potent poisons. All these natural substances are products of plant metabolism, namely metabolites.
Each plant species, even each individual plant, has its own unique spectrum of metabolites. And this metabolite profile is not rigid at all, but rather prone to constant change depending on prevailing environmental conditions. Accordingly, a diseased tomato plant differs significantly from one that is healthy in terms of its metabolite spectrum. A comparison of both metabolic profiles – diseased versus healthy – can therefore shed light on the type and severity of the disease, as well as the disease development and the plant's defense reactions.
Plant metabolomics is the research field in which these insights into plant metabolism are compiled and evaluated. The first step is a general inventory of all plant metabolites, which collectively form the plant's metabolome. Unlike DNA or proteins, metabolites are very small molecules that differ individually and are produced in their thousands by each plant. Acquiring this multitude of different substances generates data in bulk and applying bioinformatics is the only way to decipher the message that goes with it. Suitable detection and isolation methods can be used to pick out the key compounds of interesting metabolic pathways or defense reactions from the conglomerate of metabolites and determine their chemical structure. At times, these key compounds turn out to be novel lead structures for new crop protection products, cosmetics, flavorings or drugs.
For two decades or so, the IPB has researched a range of issues using metabolomics, bioinformatics and chemoinformatics. In other words, the metabolite profiles of Arabidopsis are compared with those of potato, to find out why the pathogen that causes late blight afflicts the potato plant, but fails to make headway in thale cress as soon as it penetrates the leaves. IPB scientists employ metabolomics approaches in attempts to determine which special metabolites in the leaf hairs of a wild tomato species can explain the resistance of these plants to insect feeding, as opposed to cultivated tomatoes, which no longer produce these defensive substances and are accordingly more susceptible to predators. In their constant quest to find new pharmaceutically relevant active ingredients, the chemists at the institute regularly create metabolite inventories of medicinal and crop plants from all over the world.
Acquiring metabolomic data requires powerful equipment to isolate metabolites and separate substance mixtures into their individual constituents. With machines for substance separation at its disposal, such as high-performance liquid chromatographs (HPLC) and gas chromatographs (GC), the IPB is exceptionally well equipped. It also has a wealth of highly sensitive detection and analysis devices that can shed light on the detailed structure of individual substances, such as mass and nuclear magnetic resonance (NMR) spectrometers. Over the years, the institute has compiled extensive compound and digital substance libraries. Bioinformatics methods, databases and tools have been constantly adapted and developed.
So everything needed to ensure the success of the MetaCom Program Center is in place, particularly because the existing resources are to be upgraded in future by applying artificial intelligence and machine learning. With the MetaCom project, the IPB aims to become an international reference center for specialized natural products and small molecules. This will allow the institute to visibly contribute as part of efforts to solve current challenges like climate change, plant health, infectious disease control and food security.
Prof. Alain Tissier
IPB Managing Director