Rare tropical plant develops meat appetite due to deficiency

Under certain conditions, a rare tropical plant develops into a carnivore. A research team from the universities of Hanover and Würzburg has now deciphered the mechanism responsible.

Triphyophyllum peltatum is a unique plant. Native to the tropics of West Africa, liana species are of great interest for medical and pharmacological research due to their constituents: in vitro, these medically beneficial activities show promise against pancreatic cancer and leukemia cells, among others, as well as against pancreatic cancer and leukemia cells. Pathogens that cause malaria and other diseases.

However, the plant species are also interesting from a botanical point of view: Triphyophyllum peltatum is the only known plant in the world that can become carnivorous under certain conditions. His list then includes small insects, which he captures with the help of sticky traps in the form of droplets of secretion and digests them with decomposing enzymes.

High flexibility can be seen in the leaves of the plant, which develop into three different types depending on the stage of development. While in the juvenile stage simple leaves are initially formed, later the so-called “trap leaves” can be formed, which bear a large number of sticky traps. When these traps have served their purpose, the plant either forms normal leaves again or—if the plant has entered the liana stage—is left with two hooks at the tip as a climbing support.

With regard to the expression of leaf identity, Triphyophyllum peltatum shows a high degree of flexibility: the growth stages can vary in length, and the carnivorous stage can be completely omitted or compensated for at a later stage. Thus, the plant appears to be adapted to the conditions prevailing in its habitat.

The trigger that turns a plant into a carnivore was previously unknown. One of the reasons for this was the fact that Triphyophyllum peltatum was considered very difficult to cultivate, and therefore it was difficult to study the formation of trap leaves experimentally. This problem has now been solved by scientists at Leibniz Universität Hannover (LUH) and Julius-Maximilians-Universität Würzburg (JMU).

They first succeeded in cultivating Triphyophyllum peltatum in the greenhouse of the Würzburg Botanical Garden. In Hanover, conditions have been developed for the propagation of plants in large numbers in laboratory conditions, that is, in culture vessels on well-defined nutrient media.

Professor Traude Winkelmann from the Institute of Horticultural Production Systems at Leibniz University Hannover and her colleague Anne Herwig from the Institute for Soil Sciences at LUH were involved, as well as Würzburg Professors Gerhard Bringmann (Institute of Organic Chemistry) and Rainer Heydrich (Julius von) – Institute for Biological Sciences.

Phosphorus deficiency leads to metamorphosis

But what is more important is that with the help of these plants, the research team was able to identify the factor that triggers the switch to a carnivorous lifestyle. The team has now published the results of this research in the current issue of the journal New Botany.

“We exposed the plant to different stressors, including deficiencies of various nutrients, and studied how it responded to each of them. And only in one case were we able to observe the formation of traps: in the case of a phosphorus deficiency,” says Traud Winkelmann, summarizing the central finding of the study. In fact, a drastically reduced phosphorus supply is already enough to trigger evolution into a carnivorous plant, according to the scientist.

Native to African tropical forests in nutrient-poor soils, Triphyophyllum peltatum can avoid the risk of malnutrition by forming traps and accessing the important nutrient through the digestion of insect prey. “These new discoveries represent a breakthrough as they allow for future molecular analyzes that will aid in understanding the origins of carnivores,” the scientists say.