New study shows plants use scent signals to guide growth and defense
New research has revealed that plants have a surprising ability to detect how fast nearby plants are growing by sensing airborne chemical signals. This discovery adds a new layer to how plants communicate and compete in farming environments.
These signals are known as volatile organic compounds (VOCs). They are natural chemicals released by plants into the air and are responsible for many plant scents. Plants use VOCs to interact with insects, pollinators, and other plants.
Earlier studies mainly focused on damaged plants releasing warning signals to nearby plants. However, this new research highlights that even healthy plants constantly release scent signals that influence neighboring plants.
“Healthy non-damaged plants are constantly releasing their own chemical ‘fingerprint’ into the air, and their neighbors actively read these signals to adjust not only their defenses, but their entire growth strategy,” said author Dr Velemir Ninkovic from the Swedish University of Agricultural Sciences.
“This is like a continuous conversation between neighbor's, and the finding that these background VOCs can reshape growth and gene activity opens up a new dimension in how we understand plant communication,” said Ninkovic.
In controlled experiments, plants were exposed to scents from different barley varieties. After 25 days, researchers observed changes in plant growth and gene activity. Plants exposed to fast-growing neighbors increased their own growth, while those near slow growers reduced growth and focused more on defense.
The study also found that these changes affected the entire plant, including leaves, stems, and roots. Genetic analysis showed that growth and defense responses were controlled by shifts in gene expression.
Specific scent compounds such as benzyl nitrile, linalool, and octanal play an important role in these signals. These compounds are also linked to familiar plant fragrances like citrus and lavender.
Researchers believe this type of communication is common across many plants. Understanding these natural signals could help farmers design better planting strategies, improve crop competition, and support sustainable farming practices.
Photo Credit: istock-pkujiahe