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
- Auxin cross-talk: integration of signalling pathways to control plant development (2002)
- Intercellular communication during plant development (2011)
- BBC: Plants have a hidden internet
- Net transfer of carbon between ectomycorrhizal tree species in the field (1997)
- Interplant communication of tomato plants through underground common mycorrhizal networks (2010)
- Auxin, cytokinin and the control of shoot branching (2011)
- How plants send signals with plant hormones