The Sunday Times reports (£):
Last week it was revealed that scientists at Exeter University had managed to “eavesdrop” on and film a chemical conversation between two cabbages. In the experiment, which was featured in the first episode of the BBC documentary series How to Grow a Planet, the leaves of an arabidopsis, a member of the cabbage family, were cut. The injured plant released a gas called ethyl jasmonate. This was detected by neighbouring plants, causing them to release the same chemical — in effect spreading the word that danger was in the air… Volatile compounds such as ethyl jasmonate have two direct effects: they repel herbivorous insects, such as aphids, and attract predatory species such as spiders, which further reduce the threat from plant-eaters. Chemical signalling is the botanical equivalent of sharp teeth or a tough hide.
The question is not, ‘Can they reason?’ nor, ‘Can they talk?‘ but rather, ‘Can they suffer?’