A rare species of climbing vine from West Africa can turn into a carnivore when it doesn鈥檛 get enough nutrition from the soil.
The liana Triphyophyllum peltatum grows in moist, forested hillsides in coastal regions of Sierra Leone, Liberia and Ivory Coast.
While some plants are fully carnivorous, T. peltatum is the only one known to be a part-time carnivore. It can unfurl special leaves with glands oozing sticky droplets that trap beetles and other insects, but until now it was unclear what conditions gave rise to this.
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The liana produces two other types of non-carnivorous leaf, including ones with hooks on their tips that help it to climb. But the difficulty of propagating and cultivating this vine made it challenging to figure out what triggers the formation of the insect-trapping leaves.
Now, at Leibniz University Hannover in Germany and her colleagues have managed to grow hundreds of young plants in vessels of fluid containing different concentrations of nutrients.
The team tested a range of factors, including temperature stress, treatments with stress-related hormones, and growth media that lacked one of the major nutrients 鈥� nitrogen, phosphorus or potassium.
Only plants starved of phosphorus grew carnivorous leaves. If these plants were transferred back into a control medium, new leaves emerged without the insect-trapping glands.
When dozens of the plantlets were transferred to pots of soil in a glasshouse, phosphorus deficiency triggered the emergence of carnivorous leaves among them too.
鈥淣utrient deficiency was one of the rather-to-be-expected factors, but we and others were expecting nitrogen [deficiency] to be more likely,鈥� says Winkelmann.
Carnivory may be an important survival mechanism in the plants鈥� native mountain slopes where the shallow, acidic soils become depleted of nutrients, especially phosphorus, at the end of the equatorial monsoon rains in September, she says.
New Phytologist
