Maybe carnivorous
While most plants get their nutrients from the soil, are some plants carnivours. They get their nutrients from the catching and digesting flies and other insects. And then there is Triphyophyllum peltatum, a rare tropical African liana, that is sometimes getting its nutrients from the soil, while at other times it gets those from flies. Now, German researchers have discovered what makes the plant develop fly catching leaves; a shortage of phosphate.
Like its name suggests, Triphyophyllum peltatum can make three types of leaves. A normal thirteen in a dozen leaf. In addition, they develop glandular leaves, those look more like stems with side branches each with a small red gland moist with digesting juices. And then there are the mature leaves with a hook at their tip to help the liana clime. Only those glandular leaves, the liana is not always growing them. But why was not clear.
To discover when the liana is making its glandular leaves, the researchers grew the liana in the lab. There they could expose the liana to different circumstances and analyse its reaction to those. Because glandular leaves contribute obtaining nutrients, the researchers studied what happened when there is a shortage of nitrogen, potassium, or phosphate.
The liana could not do completely without any phosphate from the soil
When there was no nutrient shortage, then the liana did not make any glandular leaves. Plants growing without potassium did not show any visible differences compares to plants that had enough potassium. Also, a shortage of nitrogen did not result in plants growing glandular leaves, although the plants did look a little pale and yellow. Only by a shortage of phosphates the researchers observed the growth of glandular leaves. The liana kept forming glandular leaves in addition, to its normal leaves as long as there was a shortage of phosphate. Up on receiving phosphate from the researchers, the plants stopped growing glandular leaves.
Still, the researchers noticed, the liana could not do completely without any phosphate from the soil. When they transferred young plants to soil without any phosphate, these plants did not survive. A little bit of phosphate was needed during the first few weeks of growth. In its presence the plant grew strong enough to make its first glandular leave after about 11 weeks enabling it to deal with further shortages.
Literature
Winkelmann, T., Bringmann, G., Herwig, A. and Hedrich, R. (2023), Carnivory on demand: phosphorus deficiency induces glandular leaves in the African liana Triphyophyllum peltatum. New Phytol. https://doi.org/10.1111/nph.18960
Plant en Zo 