Sundew Plants Detect Trapped Prey Using Glutathione

Carnivorous sundew plants can determine when they have successfully trapped prey through the chemical compound glutathione, according to a new study. The plants, known for their sticky tentacles that ensnare insects, trigger digestive processes only after detecting the presence of glutathione released by struggling prey.

This allows the sundews to avoid wasting energy on non-nutritive stimuli such as raindrops or debris. Researchers examined the biochemical signaling pathway in the plants. The study found that glutathione acts as a specific signal that initiates the production of digestive enzymes once an insect is caught.

When an insect lands on the sundew's tentacles, the physical struggle causes cells to release glutathione. The plant cells then respond to this chemical cue by activating genes responsible for digestion. This internal communication system enables the plant to confirm the presence of viable prey before committing resources to breakdown and nutrient absorption.

The process represents a form of chemical sensing that complements the plant's mechanical trapping mechanism. Sundews do not activate full digestive responses to every contact, conserving energy for actual feeding opportunities. The research provides detailed insight into how these carnivorous plants process information from their environment at a molecular level.