Plants are more 'intelligent' than previously believed and are able to make complex decisions, a new study has found.
Scientists from the Helmholtz Center for Environmental Research (UFZ) and the University of Gottingen, Germany investigated Barberry (Berberis vulgaris), which is able to abort its own seeds to prevent parasite infestation.
The results are the first ecological evidence of complex behaviour in plants, researchers said.
They indicate that this species has a structural memory, is able to differentiate between inner and outer conditions as well as anticipate future risks, they said.
"A highly specialised species of tephritid fruit fly, whose larvae actually feed on the seeds of the native Barberry, was found to have a tenfold higher population density on its new host plant, the Oregon grape," said Dr Harald Auge, a biologist at the UFZ.
Approximately 2000 berries were collected from different regions of Germany, examined for signs of piercing and then cut open to examine any infestation by the larvae of the tephritid fruit fly (Rhagoletis meigenii).
This parasite punctures the berries in order to lay its eggs inside them. If the larva is able to develop, it will often feed on all of the seeds in the berry.
A special characteristic of the Barberry is that each berry usually has two seeds and that the plant is able to stop the development of its seeds in order to save its resources. This mechanism is also employed to defend it from the tephritid fruit fly.
Using computer model calculations, scientists were able to demonstrate how those plants subjected to stress from parasite infestation reacted very differently from those without stress.
"If the Barberry aborts a fruit with only one infested seed, then the entire fruit would be lost. Instead it appears to 'speculate' that the larva could die naturally, which is a possibility. Slight chances are better than none at all," said Dr Hans-Hermann Thulke from the UFZ.
"The message of our study is therefore that plant intelligence is entering the realms of ecological possibility," Thulke said.
These new insights shed some light on the underestimated abilities of plants, while at the same time bringing up many new questions.
The study was published in the journal American Naturalist.
