Can plants warn each other about threats?
Written by
Tina Carter
Reviewed by
Prof. Martin Thorne, Ph.D.Plants have sophisticated channels for communicating with each other, using volatile organic compounds to warn their neighbors about possible impending threats. When herbivores damage plants, the plants release chemical signals into the air, such as methyl jasmonate, which is produced in response to the attack. Nearby plants "hear" the warnings, absorb the supplements, and activate the appropriate defense genes before the attackers actually arrive.
Signal Compounds
- Methyl jasmonate triggers defense gene expression
- Green leaf volatiles indicate mechanical damage
- Terpenoids carry species specific threat information
Detection Systems
- Specialized receptor proteins in plant membranes
- Stomata absorb airborne chemical messages
- Calcium ion waves amplify signals internally
Response Mechanisms
- Proteinase inhibitors reduce leaf digestibility
- Toxin production increases in vulnerable tissues
- Physical barriers like lignin strengthen cell walls
This communication takes place through complex biochemical pathways. When sagebrush is damaged, it emits methyl jasmonate, which activates neighboring plants. Corn fields under attack send forth terpenoids that attract parasitic wasps. The rapidity of the signals enables reactions in minutes and fosters networks of communal protection.
Plants communicate via distinct VOC dialects. Tomato plants produce the sesquiterpene, β-caryophyllene, in response to caterpillar attacks. Lima beans also produce specific blends of volatile chemicals in response to herbivory. This chemical language allows for accurate recognition of the nature of threats in ecosystems ranging from forests to grasslands.
The benefits of ecology extend beyond the individual benefits of plants. Forest trees communicate warnings across species boundaries. Agricultural fields develop community awareness. This airborne system operates independently, revealing a decentralized, ecosystem-based defense system in nature.
Farmers utilize this system through companion planting. Marigolds secrete limonene that protects tomatoes nearby. Intercropping a legume with corn generates signaling across the field. These tools can decrease pesticide applications by 30% while enhancing crop resilience in a natural, environmentally friendly way.
Research reveals the remarkable complexity of plant communication. For example, studies suggest that plants can remember herbivore raids, thereby altering their signals for future attacks. Other studies have shown signal discrimination among herbivore species. These studies contribute to the growing body of evidence that challenges the long-standing characterization of nonhuman organisms as lacking intelligence or a memory capacity.
Read the full article: 9 Plant Defense Mechanisms Explained
