School of Conservation Sciences

Meat-eating plants stunted by heavy metal

Sarracenia Leucophylla

Toxic effects of cadmium found to restrict the flow of water and nutrients within carnivorous plants causing their potential decline in the wild.

Scientists from BU have found evidence that the consumption of insects contaminated with a toxic metal may be a factor in the mysterious global decline of meat-eating, or carnivorous, plants.

The study, carried out by Dr Iain Green and Christopher Moody from the University’s Centre for Conservation Ecology and Environmental Change, is published in the American Chemical Society journal Environmental Science & Technology.

Entitled Assimilation of Cd and Cu by the Carnivorous Plant Sarracenia leucophylla Raf. Fed Contaminated Prey, the paper describes how meals of contaminated insects have adverse effects on carnivorous plants.

In particular, Green and Moody found that cadmium, a toxic metal found in fertilisers, metal coatings and other products, can be particularly toxic to carnivorous plants and disrupt their growth. Green and Moody fed house fly maggots contaminated with cadmium to a group of endangered white-topped pitcher plants (Sarracenia leucophylla) and found that the metal accumulated in the plants’ stems, interfering with water and nutrient uptake.

By contrast, they also fed maggots with elevated levels of copper to the plants. Copper is a nutrient important for plant health and which proved to be easily processed and controlled causing no noticeable toxic effects, the scientists say.

Green and Moody note that many species of carnivorous plants — which have the amazing ability to lure, trap and digest insects — have already become endangered through habitat loss, illegal poaching, and pollution. Their latest findings emphasise the importance of limiting carnivorous plants’ exposure to cadmium, they suggest. Both metals can accumulate in the environment and thus in insects, through improper waste disposal.

To access the full journal article, please visit: http://pubs.acs.org/stoken/presspac/presspac/full/10.1021/es9019386