How does parasitic plant find its host?

If you have ever seen the scene in the rainforest standing still suddenly becoming flexible and crawling on the ground toward fresh blood, do you think that hunting instincts are a heavenly gift? endowed with the animal world.

Recently it has been found that not only are animals capable of sniffing predators.

In the group of parasitic plants, not only direct interactions on the cell surface allow seeds to germinate on the surface of the host plant, but recently they are also found to be able to germinate on pine soil. often and then sniff to find the correct parasitic host. The parasite species mentioned in this lesson is Pink Rose (Dodder: Cuscuta pentagona), a bloodhound typical of the plant world.

Rose tree sprout is " hunting " its host (Photo: msn.com)

This particular characterization was demonstrated by Justin Runyon, a University of Pennsylvania student in a school science journal, which was later published by Science . He planted Pink Rose seeds on the soil in a filter paper belt and moistened them to germinate, then placed in any position outside the belt of a tomato plant (a host of the Rose). After only a short period of time, 80% of the Pink Rose seeds germinate and grow towards its host.

Runyon continued the second experiment using two air blowers opposite each other by 90 degrees and blowing towards the sprouting rosewood seeds, 70% of the seedlings selected the correct air blower and placed 3 tomato plants before the suction. The same results were repeated when replacing 3 tomato plants with tomato extract.

For other plants, the Pink Rose expresses two reactions that are clearly avoided (Wheat) or near (Impatiens), indicating that the multi-host plant such as red silk has a strong reaction to flying substances. vapors of different plants (substances considered as plant language). Substances that are active with Pink Silk may appear without any resistance (including mechanical injuries).

Although it is just an initial study, Runyon's results are highly appreciated by some scientists for their ability to apply in biological control for rosewood, which ranks among the top 10 most toxic plants ( according to the ranking of the US Agricultural Agency - USDA). Due to poor photosynthesis, Pink silk must adhere to and absorb nutrients from host plants to reduce the overall yield of plants, especially some types of pink silk (Goldenthread type) that can stick with dense density that can be lost. 90% of plant capacity.

Besides, there are still many doubts about the possibility that plants can communicate with each other in their own language, just like how people are skeptical about the possibility that plants growing close together can warn each other that they are being attacked because when the disease or herbivore . especially the molecules that are thought to be botanical language, have not been isolated and analyzed until now.

Tree Impatiens (Photo: ifas.ufl.edu)

Reference : Elizabeth Pennisi et al (2006), Parasitic Weed Uses Chemical Cues to Find Host Plant.Science.(313): 1867a

Nguyen Huu Hoang