Self-defense of mosses helps against snail plague

Biological active ingredient identified and successfully tested in the experiment

Iceberg lettuce is one of the favorite dishes of nudibranchs. However, if the salad is treated with oxylipins from moss plants (right leaf), it is spurned by the snail. © University of Jena
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In moss, scientists have discovered a chemical compound that deters snails and would be suitable as a biological alternative to the poisonous "snail grain". The substance, which was now identified for the first time, proved effective even when it was applied in high dilution to lettuce, a "favorite" of snails.

Snails are the enemies of every gardener: What he has sown in painstaking work, they can destroy overnight. However, the snails do not all taste the same taste: mosses avoid them. Why is that? At the end of the 19th century, the botanist and founder of the chemical ecology Ernst Stahl in Jena was already investigating this question. More than a century later, chemists at the Friedrich Schiller University Jena now have

a possible answer found on it.

"Moose are able to build chemical compounds that protect them from predators, " Professor Georg Pohnert of the University of Jena mentions a finding that Ernst Stahl had already gained from his experiments. However, the holder of the Chair of Instrumental Analysis and his team has now for the first time been able to identify these compounds and unambiguously demonstrate their antifeedant effects. The chemists around Pohnert published their research results in the current issue of the journal "Angewandte Chemie"

Oxylipins released on wounding

What spoils the snails' appetite for mosses are so-called oxylipins. "These are compounds that result from the oxidative conversion of unsaturated fatty acids when the moss is wounded, " explains Pohnert. The chemists from Jena have investigated the moss Dicranum scoparium, which is also known as the Common Forkmoss or Broom Moss

and occurs in almost all European forests. They found numerous previously unknown compounds, including new, very unusual oxylipins.

"Motivated by the observation that in other organisms oxylipins often act directly as defense metabolites or are involved in the regulation of defense reactions, we have studied the effect of these compounds in the moss plant in more detail, " says Pohnert, who has so far focused his research on the chemical Has focused on defense strategies of marine organisms.

Schnekzen verschm hen treated salad

In order to prove the possible inhibitory effect of oxylipins, the researchers from Jena brought proven experts with them on board: they "gagged" Spanish slugs, to which they planted two lettuce leaves to the Fra offered. One was treated with oxylipins extracted from the moss the other lettuce leaf was sprayed with only the solvent methanol. "The choice of snails almost exclusively fell on the leaves that did not contain oxylipins, even if we dilute the compounds 1, 000-fold compared to moss concentrations, " reports Martin Rempt, PhD student in Pohnert's team.

Alternative to the "snail grain"

According to the researchers, these findings could in the future be used to develop a natural protection against snails and other pests. This would result in a cological alternative to the so-called "snail grain", which is often a danger for birds and other predators of snails, but also for their own Represents pets. The investigations are to be extended in future to other species of moss.

(University of Jena, 11.06.2010 - NPO)