Carnivorous plants go undercover

[n2doc]

By Kate Shaw |

Just 0.2 percent of the flowering plants in the world are known to be carnivorous. We’re most familiar with Venus Flytraps, pitcher plants, and other plants that capture and digest their prey with showy techniques. However, there are other carnivorous plants that are much sneakier in their murderous ways. This week, PNAS reports that a plant with a previously unknown method of carnivory has been discovered; it catches and consumes its prey underground.

Philcoxia minensis belongs to a small genus of plants that grow in the Cerrado region of Brazil. Like many other carnivorous plants, it lives in a bright, moist, low-nutrient environment and has a nonmycorrhizal root system, meaning that it doesn't form a symbiotic relationship with fungi to help it obtain nutrients. That led researchers to suspect that it might get those nutrients through carnivory. However, its method of prey capture wasn't obvious at first glance because from the surface, there’s no sign of any type of trap.

It turns out that P. minensis uses sticky, subterranean leaves to capture nematodes, small worms that live under ground. Below the surface of the sand, the plant grows a set of tiny leaves that secrete an adhesive substance to trap the worms. Once the prey is stuck, the plant can go ahead with the business of absorbing nutrients from the worm’s body.

Carnivorous plants can get nutrition from their prey in two ways: either directly, via high enzyme activity on their leaves, or indirectly, by having microbes break the prey down (as pitcher plants do). P. minensis takes the direct route, digesting the worms itself. To test the efficiency of this process, the researchers injected nematodes with a nitrogen isotope, then fed them to P. minensis. Within 24 hours, 5 percent of the labeled nitrogen was present in the leaves, and after 48 hours, 15 percent was found in the leaves. With uptake levels this high, P. minensis seems to be more efficient at nutrient acquisition than many other carnivorous plants.



http://arstechnica.com/science/news/2012/01/carnivorous-plants-go-undercover.ars

[mopinko]

1. knr for the use of the word nematode.

killer tofu.

[Vince843]

2. Amazing.

however, it's sad to think that with climate change unique species like this are going extinct all the time. Undiscovered plant and animal species may go extinct without us not even knowing they had ever existed.

[eppur_se_muova]

3. Turnabout is fair play. There are plenty of nematodes that parasitize plants. :)

I remembered years and years ago -- I think in 7th grade biology -- seeing a film of some kind of plant that snares nematodes with microscopic filaments. Apparently it was a fungus (not a true plant): http://en.wikipedia.org/wiki/Nematophagous_fungus

I first read this in a posting by another DUer (can't remember whom):
"In short, if all the matter in the universe except the nematodes were swept away, our world would still be dimly recognizable, and if, as disembodied spirits, we could then investigate it, we should find its mountains, hills, vales, rivers, lakes, and oceans represented by a film of nematodes. The location of towns would be decipherable, since for every massing of human beings there would be a corresponding massing of certain nematodes. Trees would still stand in ghostly rows representing our streets and highways. The location of the various plants and animals would still be decipherable, and, had we sufficient knowledge, in many cases even their species could be determined by an examination of their erstwhile nematode parasites."[