For many people, the sound of raindrops can be a helpful background noise that lets them drift off to sleep. For certain seeds waiting to sprout, the opposite appears to be true. It's a wake-up call.
While the gentle patter of rain is a relaxing sound for most of us, the same sound could provide an alarm for seeds waiting to germinate.
Plants are known to respond to a range of environmental cues. Some react to touch, others to chemicals, and most to light. The idea of gravity-sensing is also well established.
Now, researchers at the Massachusetts Institute of Technology (MIT) in the United States have found that some seeds respond directly to the sound of falling rain by germinating faster.
In fact, it is as if seeds use the environmental cue of rainfall — feeling or hearing it through the vibrations it produces — to decide, as it were, it is the right time to grow.
