31 January 2018

Young researcher will open door to mysterious family of enzymes


A research team is set to explore uncharted territory in the field of plant metabolism and decipher the workings of a particular family of enzymes. It is believed that the enzymes are involved in processes that are vital for allowing plants to produce medicinal compounds, adapt to climate change and defend against pests.

To the left, a microscopic image of a germinating sorghum seed. On the right, the distribution of three different compounds, shown as blue, purple and green dyes from signals recorded using the mass spectrometry imaging (MSI) that is at the heart of Nanna Bjarnholt’s research project.

A world of uncharted secrets may be hidden in plants. Among them, the case of 'specialized metabolites', important compounds in plants that make it possible for each and every plant species to exhibit special or distinctive features. In other words, these are the compounds responsible for differentiating plants by smell, taste or chemical resistance to pests.

Associate Professor Nanna Bjarnholt has just received 10 million kroner from the VILLUM Young Investigator Programme to shed light on a particular enzyme family in plants known as glutathion transferases.

"Glutathion transferase enzymes constitute a large and mysterious family of plant enzymes, and It is believed that there are yet to be understood functions of the specialized metabolism that they engage in. If we can better understand the role of these enzymes in plants, it could ultimately open the door for new ways to use plants," according to Bjarnholt.

Important medicinal compounds in plants

Specialized metabolites don’t just help plants. Morphine, aspirin and other medicinal substances are derived from plants, and roughly 50% of our medicines are based upon specialized metabolites from various organisms.

A significant number of important medicinal substances come from difficult to cultivate plants, substances that also influence how these plants manage when planted in fields or growing in the wild. The discovery of enzymes that produce these important compounds can be used to breed better plants or to transfer the production of medicinal substances to microorganisms, which would significantly reduce pharmaceutical costs.
The glutathion transferase enzymes research project is basic science oriented, as scientists do not yet know what they will discover about the functions, or what their findings may lead to.

It is believed that there are around 200,000 different specialized metabolites found in plants around the world. The more that is understood about these compounds, the better we can harness the full potential of plants.

Technological advance opens doors

Scientists have long tried to study the roles of glutathion transferase enzymes in plants, but without much success.

"We know a lot about what these enzymes can do when we work with them in the lab. But in plants, it has been difficult to find the compounds they produce," explains Nanna Bjarnholt.

According to Bjarnholt, major technological advances now make it possible to study the problem in a different way, "The new technology allows us to keep an eye on the compounds produced by glutathion transferase enzymes and produce a detailed map of where they are found in plants."
The technology, mass spectrometry imaging (MSI), allows researchers to identify specific compounds in individual plant cells. The new technology makes it possible for Bjarnholt’s research team to focus on the portion of glutathiontransferase enzymes located in the same cells as the relevant compounds, which ought to produce the results that have been missing for decades.