science 15.12.2017 15:04

Slovenian scientists make breakthrough in understanding plant reaction to toxins

Ljubljana, 15 December - Slovenian scientists have achieved a breakthrough in understanding why certain plants are sensitive to microbial toxins, a discovery paving the way for the development of pesticides that could prevent rot and blight in major cash crops such as potatoes. Their paper was published in the journal Science on Friday.

Ljubljana
Chemistry Institute director Gregor Anderluh.
Photo: Anže Malovrh/STA

Ljubljana
Chemistry Institute researcher Vesna Hodnik.
Photo: Anže Malovrh/STA

Ljubljana
Chemistry Institute researcher Vesna Hodnik.
Photo: Anže Malovrh/STA

Ljubljana
Chemistry Institute director Gregor Anderluh.
Photo: Anže Malovrh/STA

Ljubljana
Chemistry Institute researcher Tea Lenarčič.
Photo: Anže Malovrh/STA

The discovery was made in conjunction with the University of Tübingen by Chemistry Institute early stage researcher Tea Lenarčič and senior researcher Vesna Hodnik, who are co-lead authors of the paper.

Chemistry Institute director Gregor Anderluh, a co-author of the paper, said the publication in Science, one of the most important scientific magazines in the world, was a huge recognition for his institution and for Slovenian science.

The researchers were able to precisely determine what exactly happens in the first step, when microbial toxins known as NLP proteins come into contact with plant cells.

They discovered a receptor on the surface of plant cells to which NLP proteins bind, and they were able to determine why only dicots such as potato and soy are sensitive to NLP proteins whereas monocots such as grains are not.

Now that this mechanism is clear, researchers will likely be able to develop molecules that inhibit these proteins and could be used in pesticides, according to Anderluh.

The publication in science is a follow-up to a 2009 study, which also involved Chemistry Institute researchers, that described the structure of NLP proteins and their toxicity to plants.

Many bacteria and fungi have NLP proteins which cause plants that they attack to wither away. These pests spread very quickly in crops.

The reason why NLP proteins damage only dicots - plants whose seeds have two embryonic leaves - is that dicots have different lipids in the cell membrane than monocots.

Using structural biology methods, the researchers described at the atomic level how a molecule of toxin binds to the sugar portion of the lipid.

Subsequent studies will focus on the molecular causes of damage to plant cells caused by NPL proteins, but the study has immediate practical application for the development of new pesticides.

The Chemistry Institute and the University of Tübingen have already filed for a European patent for substances that inhibit NLP proteins. They are also in talks with foreign companies to test these substances.

Prime Minister Miro Cerar commended the scientists for the achievement in a video address, saying the publication in the renowned journal would be a motivation for early-career scientists. "Science must be an instrumental part of Slovenia's vision and this achievement is a major contribution towards this goal."

The study involved 25 scientists from six countries, including eight from the Chemistry Institute and the University of Ljubljana's Biotechnical Faculty. The paper is available at http://science.sciencemag.org/content/358/6369/1383.