Plants growing close together can alert one another to environmental stress, increasing their chances of survival.
In experiments with thale cress (Arabidopsis thaliana), researchers compared plants grown in isolation with those packed closely together. When exposed to intense light, isolated plants suffered severe damage, while crowded plants coped far better.
Within an hour, densely grown plants activated more than 2,000 genes linked to protection against different stresses. Isolated plants showed little change in gene activity.
The findings suggest that stressed plants send warning signals to their neighbours. The study identified hydrogen peroxide as the signal, marking the first evidence that this molecule can pass from one plant to another, triggering shared defensive responses.
