Study elucidates how production of defensive toxins takes place in plants - ANI News

Jena [Germany], January 15 (ANI): Scientists from Max Planck Institute for Chemical Ecology describe how the plants produce defensive toxins without harming themselves and the exact mode of action of diterpene glycosides in wild tobacco.

Plants produce toxic substances to defend themselves against herbivores.

In a new study, scientists from the Max Planck Institute for Chemical Ecology in Jena and the University of Munster, Germany, were able to describe in detail the biosynthesis and exact mode of action of an important group of defensive substances, the diterpene glycosides, in wild tobacco plants.

Diterpene glycosides allow plants to fend off herbivores.

To protect themselves from their own toxins and to prevent their cell membranes from being damaged, tobacco plants store these substances in a non-toxic form, which is synthesized in a very particular way.

Researchers at the Max Planck Institute for Chemical Ecology and the University of Munster have now investigated how plants produce toxins and store them in their tissues without harming themselves.

For their experiments, they chose diterpene glycosides from Nicotiana attenuata plants, a wild tobacco species.

To their surprise, the researchers found that tobacco plants which had been transformed so they could no longer produced two proteins involved in the biosynthesis of the diterpene glycosides and thus also not form the defensive substances otherwise stored in the leaves in large amounts, showed conspicuous symptoms of self-poisoning: they were sick, unable to grow normally, and could no longer reproduce.

Sphingolipids are substances found in all animals and plants, including the enemies of wild tobacco, the larvae of the tobacco hawkmoth Manduca sexta.

In fact, Manduca sexta caterpillars, which had fed on plants without diterpene glycosides, grew significantly better than larvae, which had fed on controls that contained the defensive chemicals.

Analyses of the frass of Manduca sexta larvae, which had ingested diterpene glycosides with their food, provided further insights, as the degradation of the plant toxins during larval digestion is more or less in reverse order to the synthesis of the substances in the plant.