Triphyophyllum peltatum is an unusual plant that naturally grows in the West African tropics. It also produces compounds that could have important medical uses. Some research has indicated that compounds made by Triphyophyllum peltatum could work against pancreatic cancer, leukemia, and certain pathogens including one that causes malaria. The plant has long been used in folk medicine for a variety of reasons. Incredibly, this plant can also start eating meat if the need arises. Now scientists have learned more about how and why this plant sometimes becomes a carnivore.
The leaves of Triphyophyllum peltatum are highly dynamic, and during various developmental stages, they can take on different states and lengths. Juvenile leaves come first. They are followed by trap leaves, which carry adhesives that can snare stuff. Once the trap leaves have served their purpose, the plant will form its standard leaves, or it can enter the so-called liana stage in which two hooks form at the ends of the leaves to help the plant climb.
Although endangered and rare, the plant has some highly adaptable characteristics, and the researchers determined that when it's desperately in need of phosphorous, it can start to consume small insects. The insects become trapped in the adhesive leaves, and enzymes are secreted so the animal can be digested and consumed by the plant. The findings have been reported in the journal New Phytologist.
Phosphorus is required for plant growth, and is a critical component of different genetic, metabolic, and structural molecules. There is usually no substitute for it. Plants take up phosphorous from soil, and it is often scarce. Studies have shown that phosphorous deficiency can significantly alter gene expression in plants, in part because some of the genes that are modified when phosphorous is deficient are transcription factors, which can have a major effect on the activity of many other genes.
The researchers were able to finally determine how Triphyophyllum peltatum becomes carnivorous because they successfully cultivated it in a greenhouse at the Würzburg Botanical Garden. Growing the plant for research purposes has been very challenging up to this point. Once the investigators were able to grow large numbers of the plants, they exposed the plants to various stressful conditions to observe how the plants responded, and encourage the formation of traps on the plant's leaves. Careful research revealed that a lack of phosphorous was sufficient to trigger the development of trap leaves.
The soils that the plant naturally grows in are often deficient in nutrients, and the plant has developed an ingenious way to survive those lean times.
"These new findings are a breakthrough because they allow future molecular analyses that will help understand the origins of carnivory," noted the researchers.
Carnivory has evolved a few times in plants; there are 20 genera of carnivorous plants in 12 families.
Sources: University of Würzburg, New Phytologist