Plants ‘can recognise themselves’

PlantsMatt Walker in the BBC:

Experiments show that a sagebrush plant can recognise a genetically identical cutting growing nearby.

What’s more, the two clones communicate and cooperate with one another, to avoid being eaten by herbivores.

The findings, published in Ecology Letters, raise the tantalising possibility that plants, just like animals, often prefer to help their relatives over unrelated individuals. The ability to distinguish self from non-self is a vital one in nature.

It allows many animals to act preferentially towards others that are genetically related to themselves; for example, a female lion raising her young, or protecting other more distantly related cubs in her pride.

But the evidence that plants can do the same is limited and controversial.

Some experiments have shown that if a plant’s roots grow near to those of another unrelated plant, the two will try to compete for nutrients and water. But if a root grows close to another from the same parent plant, the two do not try to compete with one another.

However, in these experiments, when two cuttings of the same plant are then grown alongside each other, their roots still compete for resources. That implies that two separate plants cannot recognise that they are genetic kin.

[H/t: Dan Nexon]