Scientists unravel another prey capture mechanism by pitcher plants
Carnivorous plants have been known to employ a variety of techniques like nectar, smell, colour and ultraviolet florescence to lure and capture prey. But now, scientists at the Jawaharlal Nehru Tropical Botanic Gardens and Research Institute here have come up with evidence that some carnivorous plants use carbon dioxide (CO2) to attract insects and ants to their prey traps.
A study conducted by the division of Phytochemistry and Pharmacology at the institute has found that the Indian pitcher plant (Nepenthes khasiana) uses the gas, both to attract prey and to aid the digestive process. The research team led by Sabulal Baby demonstrated that the unopened pitchers of the plant are carbon dioxide-enriched, with a gas concentration of 2,500 to 5,000 ppm (parts per million), approximately 10 times that in the earth’s atmosphere.
The open Nepenthes pitchers were found to emit CO2 constantly to attract insects. The study also detected high levels of CO2 dissolved in acidic pitcher fluids, ensuring optimum activities of the digestive enzymes. The findings have been reported in Scientific Reports, a journal published by Nature.
Carnivorous plants of the genus Nepenthes supplement their nutrient deficiency by capturing insects through their leaf-evolved pitchers which act as biological traps.
The study found that the high CO2 inside the pitchers was produced by the respiration of tissues within the cavity.