Keeping in contact

Plant cells can communicate chemically

Intercellular communication – signalling between cells of the same plant – involves plant hormones, among other chemicals.

The growth factors auxin and cytokinin, for example, send conflicting messages that control the balance between growth of the main shoot and that of the branches. Auxin inhibits side-branching, while cytokinin promotes it. Other chemicals involved in cell-to-cell signalling are being identified all the time, and we now know that some types of small RNA molecules, as well as factors that control DNA transcription, are transported between plant cells.

Perhaps more surprising is that there is growing evidence that plants can have a form of chemical conversation with their neighbours. This can be mutually beneficial, such as when trees share nutrients through mycorrhizae, a symbiotic network of fungal mycelium and the plant’s roots, or when plants are alerted to the presence of danger. Studies of broad beans, for example, show that plants activate their anti-aphid defences when nearby plants are being attacked. The plants emit volatile organic compounds through the air and send underground messages through the mycorrhizal network.

Lead image:


Pictoscribe/Flickr CC BY NC


About this resource

This resource was first published in ‘Plants’ in May 2016.

Cell biology, Ecology and environment
Education levels:
16–19, Continuing professional development